20858951 has 4 divisors (see below), whose sum is σ = 20965032. Its totient is φ = 20752872.

The previous prime is 20858927. The next prime is 20858969. The reversal of 20858951 is 15985802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20858951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20858251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52745 + ... + 53138.

It is an arithmetic number, because the mean of its divisors is an integer number (5241258).

Almost surely, 2^20858951 is an apocalyptic number.

20858951 is a deficient number, since it is larger than the sum of its proper divisors (106081).

20858951 is a wasteful number, since it uses less digits than its factorization.

20858951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106080.

The product of its (nonzero) digits is 28800, while the sum is 38.

The square root of 20858951 is about 4567.1600585046. The cubic root of 20858951 is about 275.2733414402.

The spelling of 20858951 in words is "twenty million, eight hundred fifty-eight thousand, nine hundred fifty-one".