61570643656 has 32 divisors (see below), whose sum is σ = 125217209880. Its totient is φ = 28267724800.

The previous prime is 61570643653. The next prime is 61570643767. The reversal of 61570643656 is 65634607516.

It can be written as a sum of positive squares in 4 ways, for example, as 59162778756 + 2407864900 = 243234^2 + 49070^2 .

It is a super-3 number, since 3×61570643656³ (a number of 33 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (61570643653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5515465 + ... + 5526616.

Almost surely, 2^61570643656 is an apocalyptic number.

It is an amenable number.

61570643656 is an abundant number, since it is smaller than the sum of its proper divisors (63646566224).

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

61570643656 is a wasteful number, since it uses less digits than its factorization.

61570643656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11042145 (or 11042141 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 49.

The spelling of 61570643656 in words is "sixty-one billion, five hundred seventy million, six hundred forty-three thousand, six hundred fifty-six".