21287098431 has 32 divisors (see below), whose sum is σ = 31949818880. Its totient is φ = 14006193408.

The previous prime is 21287098421. The next prime is 21287098439. The reversal of 21287098431 is 13489078212.

It is a happy number.

21287098431 is a `hidden beast` number, since 2 + 128 + 7 + 0 + 98 + 431 = 666.

It is not a de Polignac number, because 21287098431 - 2¹⁸ = 21286836287 is a prime.

It is a super-2 number, since 2×21287098431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21287098439) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 950100 + ... + 972246.

It is an arithmetic number, because the mean of its divisors is an integer number (998431840).

Almost surely, 2^21287098431 is an apocalyptic number.

21287098431 is a deficient number, since it is larger than the sum of its proper divisors (10662720449).

21287098431 is a wasteful number, since it uses less digits than its factorization.

21287098431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22620 (or 22614 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 21287098431 in words is "twenty-one billion, two hundred eighty-seven million, ninety-eight thousand, four hundred thirty-one".