661963626 has 24 divisors (see below), whose sum is σ = 1435056480. Its totient is φ = 220531176.

The previous prime is 661963613. The next prime is 661963639. The reversal of 661963626 is 626369166.

661963626 is a `hidden beast` number, since 6 + 6 + 1 + 9 + 636 + 2 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (661963613) and next prime (661963639).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 26331 + ... + 44913.

It is an arithmetic number, because the mean of its divisors is an integer number (59794020).

Almost surely, 2^661963626 is an apocalyptic number.

661963626 is an abundant number, since it is smaller than the sum of its proper divisors (773092854).

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

661963626 is a wasteful number, since it uses less digits than its factorization.

661963626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20570 (or 20567 counting only the distinct ones).

The product of its digits is 419904, while the sum is 45.

The square root of 661963626 is about 25728.6537929990. The cubic root of 661963626 is about 871.5213728967.

The spelling of 661963626 in words is "six hundred sixty-one million, nine hundred sixty-three thousand, six hundred twenty-six".