20768891 has 16 divisors (see below), whose sum is σ = 24530688. Its totient is φ = 17335200.

The previous prime is 20768887. The next prime is 20768927. The reversal of 20768891 is 19886702.

It is a cyclic number.

It is not a de Polignac number, because 20768891 - 2² = 20768887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20768801) 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, 44240 + ... + 44706.

It is an arithmetic number, because the mean of its divisors is an integer number (1533168).

Almost surely, 2^20768891 is an apocalyptic number.

20768891 is a deficient number, since it is larger than the sum of its proper divisors (3761797).

20768891 is a wasteful number, since it uses less digits than its factorization.

20768891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 20768891 is about 4557.2898744758. The cubic root of 20768891 is about 274.8765991801.

The spelling of 20768891 in words is "twenty million, seven hundred sixty-eight thousand, eight hundred ninety-one".