21098015831 has 2 divisors, whose sum is σ = 21098015832. Its totient is φ = 21098015830.

The previous prime is 21098015797. The next prime is 21098015837. The reversal of 21098015831 is 13851089012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21098015831 - 2¹⁸ = 21097753687 is a prime.

It is a super-2 number, since 2×21098015831² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21098015837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10549007915 + 10549007916.

It is an arithmetic number, because the mean of its divisors is an integer number (10549007916).

Almost surely, 2^21098015831 is an apocalyptic number.

21098015831 is a deficient number, since it is larger than the sum of its proper divisors (1).

21098015831 is an equidigital number, since it uses as much as digits as its factorization.

21098015831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 38.

The spelling of 21098015831 in words is "twenty-one billion, ninety-eight million, fifteen thousand, eight hundred thirty-one".