1781792640 has 512 divisors, whose sum is σ = 6825024000. Its totient is φ = 443418624.

The previous prime is 1781792633. The next prime is 1781792647. The reversal of 1781792640 is 462971871.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1781792633) and next prime (1781792647).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781792647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 26593887 + ... + 26593953.

It is an arithmetic number, because the mean of its divisors is an integer number (13330125).

Almost surely, 2^1781792640 is an apocalyptic number.

1781792640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1781792640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3412512000).

1781792640 is an abundant number, since it is smaller than the sum of its proper divisors (5043231360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1781792640 is an frugal number, since it uses more digits than its factorization.

1781792640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The square root of 1781792640 is about 42211.2856947049. The cubic root of 1781792640 is about 1212.3249790241.

The spelling of 1781792640 in words is "one billion, seven hundred eighty-one million, seven hundred ninety-two thousand, six hundred forty".