21354015431 has 16 divisors (see below), whose sum is σ = 25822176000. Its totient is φ = 17250236928.

The previous prime is 21354015343. The next prime is 21354015437. The reversal of 21354015431 is 13451045312.

It is a cyclic number.

It is not a de Polignac number, because 21354015431 - 2¹⁸ = 21353753287 is a prime.

It is a super-2 number, since 2×21354015431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21354015394 and 21354015403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21354015437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 390281 + ... + 441618.

It is an arithmetic number, because the mean of its divisors is an integer number (1613886000).

Almost surely, 2^21354015431 is an apocalyptic number.

21354015431 is a deficient number, since it is larger than the sum of its proper divisors (4468160569).

21354015431 is a wasteful number, since it uses less digits than its factorization.

21354015431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832118.

The product of its (nonzero) digits is 7200, while the sum is 29.

The spelling of 21354015431 in words is "twenty-one billion, three hundred fifty-four million, fifteen thousand, four hundred thirty-one".