20757490 has 16 divisors (see below), whose sum is σ = 40237848. Its totient is φ = 7664256.

The previous prime is 20757479. The next prime is 20757511. The reversal of 20757490 is 9475702.

It can be written as a sum of positive squares in 4 ways, for example, as 5461569 + 15295921 = 2337^2 + 3911^2 .

It is a super-2 number, since 2×20757490² = 861746782200200, which contains 22 as substring.

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, 79707 + ... + 79966.

Almost surely, 2^20757490 is an apocalyptic number.

20757490 is a deficient number, since it is larger than the sum of its proper divisors (19480358).

20757490 is a wasteful number, since it uses less digits than its factorization.

20757490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159693.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 20757490 is about 4556.0388497027. The cubic root of 20757490 is about 274.8262925023.

The spelling of 20757490 in words is "twenty million, seven hundred fifty-seven thousand, four hundred ninety".