665631025026 has 32 divisors (see below), whose sum is σ = 1537714456128. Its totient is φ = 189841290240.

The previous prime is 665631025021. The next prime is 665631025039. The reversal of 665631025026 is 620520136566.

It is a super-2 number, since 2×665631025026² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (665631025021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 296625895 + ... + 296628138.

It is an arithmetic number, because the mean of its divisors is an integer number (48053576754).

Almost surely, 2^665631025026 is an apocalyptic number.

665631025026 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

665631025026 is an abundant number, since it is smaller than the sum of its proper divisors (872083431102).

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

665631025026 is a wasteful number, since it uses less digits than its factorization.

665631025026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593254066.

The product of its (nonzero) digits is 388800, while the sum is 42.

The spelling of 665631025026 in words is "six hundred sixty-five billion, six hundred thirty-one million, twenty-five thousand, twenty-six".