21034402402 has 16 divisors (see below), whose sum is σ = 34279350840. Its totient is φ = 9622271232.

The previous prime is 21034402399. The next prime is 21034402429. The reversal of 21034402402 is 20420443012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 8638029481 + 12396372921 = 92941^2 + 111339^2 .

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, 3576777 + ... + 3582652.

Almost surely, 2^21034402402 is an apocalyptic number.

21034402402 is a deficient number, since it is larger than the sum of its proper divisors (13244948438).

21034402402 is a wasteful number, since it uses less digits than its factorization.

21034402402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7159557.

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21034402402 its reverse (20420443012), we get a palindrome (41454845414).

The spelling of 21034402402 in words is "twenty-one billion, thirty-four million, four hundred two thousand, four hundred two".