20956851 has 6 divisors (see below), whose sum is σ = 30271020. Its totient is φ = 13971228.

The previous prime is 20956843. The next prime is 20956853. The reversal of 20956851 is 15865902.

It is a happy number.

It is not a de Polignac number, because 20956851 - 2³ = 20956843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20956853) 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, 1164261 + ... + 1164278.

It is an arithmetic number, because the mean of its divisors is an integer number (5045170).

Almost surely, 2^20956851 is an apocalyptic number.

20956851 is a deficient number, since it is larger than the sum of its proper divisors (9314169).

20956851 is a wasteful number, since it uses less digits than its factorization.

20956851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2328545 (or 2328542 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 20956851 is about 4577.8653322264. The cubic root of 20956851 is about 275.7033280399.

The spelling of 20956851 in words is "twenty million, nine hundred fifty-six thousand, eight hundred fifty-one".