1781825820 has 48 divisors (see below), whose sum is σ = 4991414400. Its totient is φ = 474934336.

The previous prime is 1781825819. The next prime is 1781825827. The reversal of 1781825820 is 285281871.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781825827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 156439 + ... + 167441.

It is an arithmetic number, because the mean of its divisors is an integer number (103987800).

Almost surely, 2^1781825820 is an apocalyptic number.

1781825820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1781825820 is an abundant number, since it is smaller than the sum of its proper divisors (3209588580).

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

1781825820 is a wasteful number, since it uses less digits than its factorization.

1781825820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13714 (or 13712 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 42.

The square root of 1781825820 is about 42211.6787157298. The cubic root of 1781825820 is about 1212.3325041596.

The spelling of 1781825820 in words is "one billion, seven hundred eighty-one million, eight hundred twenty-five thousand, eight hundred twenty".