20951559 has 6 divisors (see below), whose sum is σ = 30263376. Its totient is φ = 13967700.

The previous prime is 20951537. The next prime is 20951573. The reversal of 20951559 is 95515902.

It is not a de Polignac number, because 20951559 - 2⁵ = 20951527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20951159) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1163967 + ... + 1163984.

It is an arithmetic number, because the mean of its divisors is an integer number (5043896).

Almost surely, 2^20951559 is an apocalyptic number.

20951559 is a deficient number, since it is larger than the sum of its proper divisors (9311817).

20951559 is a wasteful number, since it uses less digits than its factorization.

20951559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2327957 (or 2327954 counting only the distinct ones).

The product of its (nonzero) digits is 20250, while the sum is 36.

The square root of 20951559 is about 4577.2872970789. The cubic root of 20951559 is about 275.6801193235.

The spelling of 20951559 in words is "twenty million, nine hundred fifty-one thousand, five hundred fifty-nine".