20402404645 has 24 divisors (see below), whose sum is σ = 28489504248. Its totient is φ = 13985596800.

The previous prime is 20402404619. The next prime is 20402404651. The reversal of 20402404645 is 54640420402.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 4922565921 + 15479838724 = 70161^2 + 124418^2 .

It is not a de Polignac number, because 20402404645 - 2²³ = 20394016037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 835915 + ... + 859975.

It is an arithmetic number, because the mean of its divisors is an integer number (1187062677).

Almost surely, 2^20402404645 is an apocalyptic number.

It is an amenable number.

20402404645 is a deficient number, since it is larger than the sum of its proper divisors (8087099603).

20402404645 is a wasteful number, since it uses less digits than its factorization.

20402404645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27541 (or 27534 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 31.

The spelling of 20402404645 in words is "twenty billion, four hundred two million, four hundred four thousand, six hundred forty-five".