20129895 has 12 divisors (see below), whose sum is σ = 34891896. Its totient is φ = 10735920.

The previous prime is 20129869. The next prime is 20129897. The reversal of 20129895 is 59892102.

It is not a de Polignac number, because 20129895 - 2⁸ = 20129639 is a prime.

It is a super-2 number, since 2×20129895² = 810425345422050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20129897) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 223621 + ... + 223710.

It is an arithmetic number, because the mean of its divisors is an integer number (2907658).

Almost surely, 2^20129895 is an apocalyptic number.

20129895 is a deficient number, since it is larger than the sum of its proper divisors (14762001).

20129895 is a wasteful number, since it uses less digits than its factorization.

20129895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447342 (or 447339 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 20129895 is about 4486.6351534307. The cubic root of 20129895 is about 272.0281428133.

The spelling of 20129895 in words is "twenty million, one hundred twenty-nine thousand, eight hundred ninety-five".