20956013 has 16 divisors (see below), whose sum is σ = 23802240. Its totient is φ = 18304704.

The previous prime is 20956003. The next prime is 20956021. The reversal of 20956013 is 31065902.

It is a cyclic number.

It is not a de Polignac number, because 20956013 - 2⁴ = 20955997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20956003) 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, 32270 + ... + 32912.

It is an arithmetic number, because the mean of its divisors is an integer number (1487640).

Almost surely, 2^20956013 is an apocalyptic number.

20956013 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

20956013 is a deficient number, since it is larger than the sum of its proper divisors (2846227).

20956013 is a wasteful number, since it uses less digits than its factorization.

20956013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 788.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 20956013 is about 4577.7738039357. The cubic root of 20956013 is about 275.6996531483.

The spelling of 20956013 in words is "twenty million, nine hundred fifty-six thousand, thirteen".