20642500 has 60 divisors (see below), whose sum is σ = 47234880. Its totient is φ = 7876000.

The previous prime is 20642467. The next prime is 20642509. The reversal of 20642500 is 524602.

It is a super-2 number, since 2×20642500² = 852225612500000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20642509) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 57321 + ... + 57679.

It is an arithmetic number, because the mean of its divisors is an integer number (787248).

Almost surely, 2^20642500 is an apocalyptic number.

20642500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20642500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23617440).

20642500 is an abundant number, since it is smaller than the sum of its proper divisors (26592380).

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

20642500 is a wasteful number, since it uses less digits than its factorization.

20642500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 389 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 20642500 is about 4543.4018092174. The cubic root of 20642500 is about 274.3178686159.

The spelling of 20642500 in words is "twenty million, six hundred forty-two thousand, five hundred".