20129890 has 16 divisors (see below), whose sum is σ = 39528000. Its totient is φ = 7319920.

The previous prime is 20129869. The next prime is 20129897. The reversal of 20129890 is 9892102.

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 7 ways as a sum of consecutive naturals, for example, 91390 + ... + 91609.

It is an arithmetic number, because the mean of its divisors is an integer number (2470500).

Almost surely, 2^20129890 is an apocalyptic number.

20129890 is a deficient number, since it is larger than the sum of its proper divisors (19398110).

20129890 is a wasteful number, since it uses less digits than its factorization.

20129890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183017.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 20129890 is about 4486.6345962202. The cubic root of 20129890 is about 272.0281202905.

The spelling of 20129890 in words is "twenty million, one hundred twenty-nine thousand, eight hundred ninety".