1642660920 has 192 divisors, whose sum is σ = 5763700800. Its totient is φ = 404490240.

The previous prime is 1642660919. The next prime is 1642660927. The reversal of 1642660920 is 290662461.

1642660920 is a `hidden beast` number, since 1 + 6 + 4 + 26 + 609 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1642660927) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 236700 + ... + 243540.

It is an arithmetic number, because the mean of its divisors is an integer number (30019275).

Almost surely, 2^1642660920 is an apocalyptic number.

1642660920 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 1642660920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2881850400).

1642660920 is an abundant number, since it is smaller than the sum of its proper divisors (4121039880).

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

1642660920 is a wasteful number, since it uses less digits than its factorization.

1642660920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6910 (or 6903 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 1642660920 is about 40529.7535151646. The cubic root of 1642660920 is about 1179.9111586853.

The spelling of 1642660920 in words is "one billion, six hundred forty-two million, six hundred sixty thousand, nine hundred twenty".