20400402402 has 12 divisors (see below), whose sum is σ = 44200871910. Its totient is φ = 6800134128.

The previous prime is 20400402401. The next prime is 20400402403. The reversal of 20400402402 is 20420400402.

20400402402 is a `hidden beast` number, since 20 + 400 + 4 + 0 + 240 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (20400402401) and next prime (20400402403).

It can be written as a sum of positive squares in only one way, i.e., 19496257641 + 904144761 = 139629^2 + 30069^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1133355689 = 20400402402 / (2 + 0 + 4 + 0 + 0 + 4 + 0 + 2 + 4 + 0 + 2).

It is not an unprimeable number, because it can be changed into a prime (20400402401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 566677827 + ... + 566677862.

Almost surely, 2^20400402402 is an apocalyptic number.

20400402402 is an abundant number, since it is smaller than the sum of its proper divisors (23800469508).

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

20400402402 is a wasteful number, since it uses less digits than its factorization.

20400402402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133355697 (or 1133355694 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 18.

Adding to 20400402402 its reverse (20420400402), we get a palindrome (40820802804).

The spelling of 20400402402 in words is "twenty billion, four hundred million, four hundred two thousand, four hundred two".