20402642240 has 28 divisors (see below), whose sum is σ = 48583792596. Its totient is φ = 8161056768.

The previous prime is 20402642209. The next prime is 20402642287. The reversal of 20402642240 is 4224620402.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13385564416 + 7017077824 = 115696^2 + 83768^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31878809 + ... + 31879448.

Almost surely, 2^20402642240 is an apocalyptic number.

20402642240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20402642240 is an abundant number, since it is smaller than the sum of its proper divisors (28181150356).

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

20402642240 is an equidigital number, since it uses as much as digits as its factorization.

20402642240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63758274 (or 63758264 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 26.

The spelling of 20402642240 in words is "twenty billion, four hundred two million, six hundred forty-two thousand, two hundred forty".