1656561942 has 80 divisors (see below), whose sum is σ = 4379139072. Its totient is φ = 458025840.

The previous prime is 1656561931. The next prime is 1656561943. The reversal of 1656561942 is 2491656561.

It is a super-2 number, since 2×1656561942² = 5488394935365622728, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1656561943) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11593 + ... + 58715.

Almost surely, 2^1656561942 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1656561942, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2189569536).

1656561942 is an abundant number, since it is smaller than the sum of its proper divisors (2722577130).

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

1656561942 is a wasteful number, since it uses less digits than its factorization.

1656561942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47175 (or 47166 counting only the distinct ones).

The product of its digits is 388800, while the sum is 45.

The square root of 1656561942 is about 40700.8837987580. The cubic root of 1656561942 is about 1183.2301475764.

The spelling of 1656561942 in words is "one billion, six hundred fifty-six million, five hundred sixty-one thousand, nine hundred forty-two".