21042898931 has 2 divisors, whose sum is σ = 21042898932. Its totient is φ = 21042898930.

The previous prime is 21042898913. The next prime is 21042898939. The reversal of 21042898931 is 13989824012.

Together with previous prime (21042898913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21042898931 - 2¹⁸ = 21042636787 is a prime.

It is a super-2 number, since 2×21042898931² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21042898939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521449465 + 10521449466.

It is an arithmetic number, because the mean of its divisors is an integer number (10521449466).

Almost surely, 2^21042898931 is an apocalyptic number.

21042898931 is a deficient number, since it is larger than the sum of its proper divisors (1).

21042898931 is an equidigital number, since it uses as much as digits as its factorization.

21042898931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 47.

The spelling of 21042898931 in words is "twenty-one billion, forty-two million, eight hundred ninety-eight thousand, nine hundred thirty-one".