21430402431 has 4 divisors (see below), whose sum is σ = 28573869912. Its totient is φ = 14286934952.

The previous prime is 21430402429. The next prime is 21430402439. The reversal of 21430402431 is 13420403412.

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

It is a cyclic number.

It is not a de Polignac number, because 21430402431 - 2¹ = 21430402429 is a prime.

It is a super-2 number, since 2×21430402431² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21430402439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3571733736 + ... + 3571733741.

It is an arithmetic number, because the mean of its divisors is an integer number (7143467478).

Almost surely, 2^21430402431 is an apocalyptic number.

21430402431 is a deficient number, since it is larger than the sum of its proper divisors (7143467481).

21430402431 is an equidigital number, since it uses as much as digits as its factorization.

21430402431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7143467480.

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21430402431 its reverse (13420403412), we get a palindrome (34850805843).

The spelling of 21430402431 in words is "twenty-one billion, four hundred thirty million, four hundred two thousand, four hundred thirty-one".