20157390 has 96 divisors (see below), whose sum is σ = 59179680. Its totient is φ = 4878720.

The previous prime is 20157383. The next prime is 20157391. The reversal of 20157390 is 9375102.

20157390 is a `hidden beast` number, since 2 + 0 + 1 + 573 + 90 = 666.

It is a super-2 number, since 2×20157390² = 812640743224200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20157391) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 32362 + ... + 32978.

It is an arithmetic number, because the mean of its divisors is an integer number (616455).

Almost surely, 2^20157390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20157390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29589840).

20157390 is an abundant number, since it is smaller than the sum of its proper divisors (39022290).

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

20157390 is a wasteful number, since it uses less digits than its factorization.

20157390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655 (or 638 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 20157390 is about 4489.6982081205. The cubic root of 20157390 is about 272.1519389722.

The spelling of 20157390 in words is "twenty million, one hundred fifty-seven thousand, three hundred ninety".