21115402312 has 16 divisors (see below), whose sum is σ = 39593369340. Its totient is φ = 10557170496.

The previous prime is 21115402277. The next prime is 21115402327. The reversal of 21115402312 is 21320451112.

It can be written as a sum of positive squares in 2 ways, for example, as 17190880996 + 3924521316 = 131114^2 + 62646^2 .

It is a super-2 number, since 2×21115402312² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140838 + ... + 249130.

Almost surely, 2^21115402312 is an apocalyptic number.

It is an amenable number.

21115402312 is a deficient number, since it is larger than the sum of its proper divisors (18477967028).

21115402312 is a wasteful number, since it uses less digits than its factorization.

21115402312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132672 (or 132668 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

Adding to 21115402312 its reverse (21320451112), we get a palindrome (42435853424).

The spelling of 21115402312 in words is "twenty-one billion, one hundred fifteen million, four hundred two thousand, three hundred twelve".