660657642 has 24 divisors (see below), whose sum is σ = 1368459456. Its totient is φ = 212623824.

The previous prime is 660657637. The next prime is 660657643. The reversal of 660657642 is 246756066.

It is a junction number, because it is equal to n+sod(n) for n = 660657594 and 660657603.

It is not an unprimeable number, because it can be changed into a prime (660657643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 60418 + ... + 70509.

It is an arithmetic number, because the mean of its divisors is an integer number (57019144).

Almost surely, 2^660657642 is an apocalyptic number.

660657642 is an abundant number, since it is smaller than the sum of its proper divisors (707801814).

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

660657642 is a wasteful number, since it uses less digits than its factorization.

660657642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130990 (or 130961 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 42.

The square root of 660657642 is about 25703.2613105808. The cubic root of 660657642 is about 870.9478558349.

The spelling of 660657642 in words is "six hundred sixty million, six hundred fifty-seven thousand, six hundred forty-two".