661856013942 has 16 divisors (see below), whose sum is σ = 1325109834432. Its totient is φ = 220385703560.

The previous prime is 661856013899. The next prime is 661856013953. The reversal of 661856013942 is 249310658166.

661856013942 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58235784 + ... + 58247147.

It is an arithmetic number, because the mean of its divisors is an integer number (82819364652).

Almost surely, 2^661856013942 is an apocalyptic number.

661856013942 is an abundant number, since it is smaller than the sum of its proper divisors (663253820490).

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

661856013942 is a wasteful number, since it uses less digits than its factorization.

661856013942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116483883.

The product of its (nonzero) digits is 1866240, while the sum is 51.

The spelling of 661856013942 in words is "six hundred sixty-one billion, eight hundred fifty-six million, thirteen thousand, nine hundred forty-two".