20304131240 has 32 divisors (see below), whose sum is σ = 45731143080. Its totient is φ = 8113324032.

The previous prime is 20304131227. The next prime is 20304131251. The reversal of 20304131240 is 4213140302.

It can be written as a sum of positive squares in 4 ways, for example, as 16474749316 + 3829381924 = 128354^2 + 61882^2 .

It is a super-2 number, since 2×20304131240² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 220697 + ... + 298856.

Almost surely, 2^20304131240 is an apocalyptic number.

20304131240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20304131240 is an abundant number, since it is smaller than the sum of its proper divisors (25427011840).

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

20304131240 is a wasteful number, since it uses less digits than its factorization.

20304131240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520541 (or 520537 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 20304131240 its reverse (4213140302), we get a palindrome (24517271542).

The spelling of 20304131240 in words is "twenty billion, three hundred four million, one hundred thirty-one thousand, two hundred forty".