21034505431 has 4 divisors (see below), whose sum is σ = 21034858432. Its totient is φ = 21034152432.

The previous prime is 21034505413. The next prime is 21034505483. The reversal of 21034505431 is 13450543012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21034505431 is a prime.

It is a super-2 number, since 2×21034505431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21034505431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21034505411) 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 in 3 ways as a sum of consecutive naturals, for example, 62631 + ... + 214456.

It is an arithmetic number, because the mean of its divisors is an integer number (5258714608).

Almost surely, 2^21034505431 is an apocalyptic number.

21034505431 is a deficient number, since it is larger than the sum of its proper divisors (353001).

21034505431 is an equidigital number, since it uses as much as digits as its factorization.

21034505431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353000.

The product of its (nonzero) digits is 7200, while the sum is 28.

The spelling of 21034505431 in words is "twenty-one billion, thirty-four million, five hundred five thousand, four hundred thirty-one".