20401880 has 16 divisors (see below), whose sum is σ = 45904320. Its totient is φ = 8160736.

The previous prime is 20401867. The next prime is 20401919. The reversal of 20401880 is 8810402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254984 + ... + 255063.

It is an arithmetic number, because the mean of its divisors is an integer number (2869020).

Almost surely, 2^20401880 is an apocalyptic number.

20401880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20401880 is an abundant number, since it is smaller than the sum of its proper divisors (25502440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20401880 is a wasteful number, since it uses less digits than its factorization.

20401880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510058 (or 510054 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 20401880 is about 4516.8440309579. The cubic root of 20401880 is about 273.2478349815.

The spelling of 20401880 in words is "twenty million, four hundred one thousand, eight hundred eighty".