20256129 has 16 divisors (see below), whose sum is σ = 31775040. Its totient is φ = 12709440.

The previous prime is 20256127. The next prime is 20256143. The reversal of 20256129 is 92165202.

20256129 is a `hidden beast` number, since 20 + 25 + 612 + 9 = 666.

It is not a de Polignac number, because 20256129 - 2¹ = 20256127 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20256127) 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, 21607 + ... + 22524.

It is an arithmetic number, because the mean of its divisors is an integer number (1985940).

Almost surely, 2^20256129 is an apocalyptic number.

It is an amenable number.

20256129 is a deficient number, since it is larger than the sum of its proper divisors (11518911).

20256129 is a wasteful number, since it uses less digits than its factorization.

20256129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44157 (or 44151 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 20256129 is about 4500.6809484788. The cubic root of 20256129 is about 272.5955852426.

The spelling of 20256129 in words is "twenty million, two hundred fifty-six thousand, one hundred twenty-nine".