65661400 has 48 divisors (see below), whose sum is σ = 174475440. Its totient is φ = 22512000.

The previous prime is 65661373. The next prime is 65661457. The reversal of 65661400 is 416656.

It is a super-2 number, since 2×65661400² = 8622838899920000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

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, 22051 + ... + 24850.

It is an arithmetic number, because the mean of its divisors is an integer number (3634905).

Almost surely, 2^65661400 is an apocalyptic number.

It is an amenable number.

65661400 is an abundant number, since it is smaller than the sum of its proper divisors (108814040).

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

65661400 is a wasteful number, since it uses less digits than its factorization.

65661400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46924 (or 46915 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 65661400 is about 8103.1722183352. The cubic root of 65661400 is about 403.4317239795.

The spelling of 65661400 in words is "sixty-five million, six hundred sixty-one thousand, four hundred".