20215740 has 24 divisors (see below), whose sum is σ = 56604240. Its totient is φ = 5390848.

The previous prime is 20215739. The next prime is 20215757. The reversal of 20215740 is 4751202.

It is a super-2 number, since 2×20215740² = 817352287495200, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168405 + ... + 168524.

It is an arithmetic number, because the mean of its divisors is an integer number (2358510).

Almost surely, 2^20215740 is an apocalyptic number.

20215740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20215740 is an abundant number, since it is smaller than the sum of its proper divisors (36388500).

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

20215740 is a wasteful number, since it uses less digits than its factorization.

20215740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336941 (or 336939 counting only the distinct ones).

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

The square root of 20215740 is about 4496.1917218909. The cubic root of 20215740 is about 272.4142872136.

Adding to 20215740 its reverse (4751202), we get a palindrome (24966942).

The spelling of 20215740 in words is "twenty million, two hundred fifteen thousand, seven hundred forty".