68561991506 has 16 divisors (see below), whose sum is σ = 103846147200. Its totient is φ = 33948000240.

The previous prime is 68561991481. The next prime is 68561991523. The reversal of 68561991506 is 60519916586.

It is a happy number.

It is a super-2 number, since 2×68561991506² (a number of 22 digits) contains 22 as substring.

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, 248906 + ... + 446181.

It is an arithmetic number, because the mean of its divisors is an integer number (6490384200).

Almost surely, 2^68561991506 is an apocalyptic number.

68561991506 is a deficient number, since it is larger than the sum of its proper divisors (35284155694).

68561991506 is a wasteful number, since it uses less digits than its factorization.

68561991506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 695569.

The product of its (nonzero) digits is 3499200, while the sum is 56.

The spelling of 68561991506 in words is "sixty-eight billion, five hundred sixty-one million, nine hundred ninety-one thousand, five hundred six".