66431958 has 32 divisors (see below), whose sum is σ = 139041792. Its totient is φ = 21120000.

The previous prime is 66431941. The next prime is 66431987. The reversal of 66431958 is 85913466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88083 + ... + 88833.

It is an arithmetic number, because the mean of its divisors is an integer number (4345056).

Almost surely, 2^66431958 is an apocalyptic number.

66431958 is an abundant number, since it is smaller than the sum of its proper divisors (72609834).

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

66431958 is a wasteful number, since it uses less digits than its factorization.

66431958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1420.

The product of its digits is 155520, while the sum is 42.

The square root of 66431958 is about 8150.5802247447. The cubic root of 66431958 is about 405.0037250077.

The spelling of 66431958 in words is "sixty-six million, four hundred thirty-one thousand, nine hundred fifty-eight".