65681990 has 32 divisors (see below), whose sum is σ = 129406464. Its totient is φ = 23804640.

The previous prime is 65681977. The next prime is 65682007. The reversal of 65681990 is 9918656.

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, 39557 + ... + 41183.

It is an arithmetic number, because the mean of its divisors is an integer number (4043952).

Almost surely, 2^65681990 is an apocalyptic number.

65681990 is a deficient number, since it is larger than the sum of its proper divisors (63724474).

65681990 is a wasteful number, since it uses less digits than its factorization.

65681990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2012.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 65681990 is about 8104.4426088412. The cubic root of 65681990 is about 403.4738887373.

It can be divided in two parts, 6568 and 1990, that added together give a palindrome (8558).

The spelling of 65681990 in words is "sixty-five million, six hundred eighty-one thousand, nine hundred ninety".