21003402402 has 12 divisors (see below), whose sum is σ = 45507371910. Its totient is φ = 7001134128.

The previous prime is 21003402377. The next prime is 21003402419. The reversal of 21003402402 is 20420430012.

It can be written as a sum of positive squares in only one way, i.e., 16824943521 + 4178458881 = 129711^2 + 64641^2 .

It is a super-2 number, since 2×21003402402² (a number of 21 digits) contains 22 as substring.

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: 1166855689 = 21003402402 / (2 + 1 + 0 + 0 + 3 + 4 + 0 + 2 + 4 + 0 + 2).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 583427827 + ... + 583427862.

Almost surely, 2^21003402402 is an apocalyptic number.

21003402402 is an abundant number, since it is smaller than the sum of its proper divisors (24503969508).

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

21003402402 is a wasteful number, since it uses less digits than its factorization.

21003402402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1166855697 (or 1166855694 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21003402402 its reverse (20420430012), we get a palindrome (41423832414).

The spelling of 21003402402 in words is "twenty-one billion, three million, four hundred two thousand, four hundred two".