20642820 has 48 divisors (see below), whose sum is σ = 63056448. Its totient is φ = 5004160.

The previous prime is 20642789. The next prime is 20642821. The reversal of 20642820 is 2824602.

It is a super-2 number, since 2×20642820² = 852252035104800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20642821) 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, 14979 + ... + 16298.

It is an arithmetic number, because the mean of its divisors is an integer number (1313676).

Almost surely, 2^20642820 is an apocalyptic number.

20642820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20642820 is an abundant number, since it is smaller than the sum of its proper divisors (42413628).

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

20642820 is a wasteful number, since it uses less digits than its factorization.

20642820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31300 (or 31298 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 20642820 is about 4543.4370249845. The cubic root of 20642820 is about 274.3192861003.

It can be divided in two parts, 2064 and 2820, that added together give a palindrome (4884).

The spelling of 20642820 in words is "twenty million, six hundred forty-two thousand, eight hundred twenty".