20157240 has 128 divisors (see below), whose sum is σ = 65862720. Its totient is φ = 4915200.

The previous prime is 20157229. The next prime is 20157253. The reversal of 20157240 is 4275102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 83520 + ... + 83760.

Almost surely, 2^20157240 is an apocalyptic number.

20157240 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 20157240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32931360).

20157240 is an abundant number, since it is smaller than the sum of its proper divisors (45705480).

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

20157240 is a wasteful number, since it uses less digits than its factorization.

20157240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313 (or 309 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 20157240 is about 4489.6815031804. The cubic root of 20157240 is about 272.1512639032.

The spelling of 20157240 in words is "twenty million, one hundred fifty-seven thousand, two hundred forty".