20861764 has 24 divisors (see below), whose sum is σ = 45517248. Its totient is φ = 8127840.

The previous prime is 20861761. The next prime is 20861773. The reversal of 20861764 is 46716802.

It is not an unprimeable number, because it can be changed into a prime (20861761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33559 + ... + 34174.

It is an arithmetic number, because the mean of its divisors is an integer number (1896552).

Almost surely, 2^20861764 is an apocalyptic number.

It is an amenable number.

20861764 is an abundant number, since it is smaller than the sum of its proper divisors (24655484).

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

20861764 is a wasteful number, since it uses less digits than its factorization.

20861764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67755 (or 67753 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 20861764 is about 4567.4680075508. The cubic root of 20861764 is about 275.2857151706.

The spelling of 20861764 in words is "twenty million, eight hundred sixty-one thousand, seven hundred sixty-four".