20157980 has 24 divisors (see below), whose sum is σ = 42456960. Its totient is φ = 8039360.

The previous prime is 20157953. The next prime is 20157983. The reversal of 20157980 is 8975102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20157983) 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, 6485 + ... + 9075.

It is an arithmetic number, because the mean of its divisors is an integer number (1769040).

Almost surely, 2^20157980 is an apocalyptic number.

20157980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20157980 is an abundant number, since it is smaller than the sum of its proper divisors (22298980).

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

20157980 is a wasteful number, since it uses less digits than its factorization.

20157980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2989 (or 2987 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 20157980 is about 4489.7639136151. The cubic root of 20157980 is about 272.1545942114.

The spelling of 20157980 in words is "twenty million, one hundred fifty-seven thousand, nine hundred eighty".