668771540 has 24 divisors (see below), whose sum is σ = 1412836992. Its totient is φ = 265905440.

The previous prime is 668771527. The next prime is 668771567. The reversal of 668771540 is 45177866.

It is a junction number, because it is equal to n+sod(n) for n = 668771491 and 668771500.

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, 96776 + ... + 103455.

It is an arithmetic number, because the mean of its divisors is an integer number (58868208).

Almost surely, 2^668771540 is an apocalyptic number.

It is an amenable number.

668771540 is an abundant number, since it is smaller than the sum of its proper divisors (744065452).

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

668771540 is a wasteful number, since it uses less digits than its factorization.

668771540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200407 (or 200405 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 44.

The square root of 668771540 is about 25860.6175486975. The cubic root of 668771540 is about 874.4988869446.

The spelling of 668771540 in words is "six hundred sixty-eight million, seven hundred seventy-one thousand, five hundred forty".