20751664 has 20 divisors (see below), whose sum is σ = 40504104. Its totient is φ = 10299008.

The previous prime is 20751631. The next prime is 20751683. The reversal of 20751664 is 46615702.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2542 + ... + 6925.

Almost surely, 2^20751664 is an apocalyptic number.

It is an amenable number.

20751664 is a deficient number, since it is larger than the sum of its proper divisors (19752440).

20751664 is a wasteful number, since it uses less digits than its factorization.

20751664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9612 (or 9606 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20751664 is about 4555.3994336392. The cubic root of 20751664 is about 274.8005782854.

The spelling of 20751664 in words is "twenty million, seven hundred fifty-one thousand, six hundred sixty-four".