20156740 has 48 divisors (see below), whose sum is σ = 45722880. Its totient is φ = 7441280.

The previous prime is 20156737. The next prime is 20156753. The reversal of 20156740 is 4765102.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12585 + ... + 14095.

It is an arithmetic number, because the mean of its divisors is an integer number (952560).

Almost surely, 2^20156740 is an apocalyptic number.

20156740 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 20156740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22861440).

20156740 is an abundant number, since it is smaller than the sum of its proper divisors (25566140).

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

20156740 is a wasteful number, since it uses less digits than its factorization.

20156740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1572 (or 1570 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 20156740 is about 4489.6258195979. The cubic root of 20156740 is about 272.1490136487.

The spelling of 20156740 in words is "twenty million, one hundred fifty-six thousand, seven hundred forty".