21035342431 has 4 divisors (see below), whose sum is σ = 21113541000. Its totient is φ = 20957143864.

The previous prime is 21035342429. The next prime is 21035342483. The reversal of 21035342431 is 13424353012.

It is a happy number.

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 21035342431 - 2¹ = 21035342429 is a prime.

It is a super-2 number, since 2×21035342431² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21035342431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21035349431) 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, 39098881 + ... + 39099418.

It is an arithmetic number, because the mean of its divisors is an integer number (5278385250).

Almost surely, 2^21035342431 is an apocalyptic number.

21035342431 is a deficient number, since it is larger than the sum of its proper divisors (78198569).

21035342431 is an equidigital number, since it uses as much as digits as its factorization.

21035342431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78198568.

The product of its (nonzero) digits is 8640, while the sum is 28.

Adding to 21035342431 its reverse (13424353012), we get a palindrome (34459695443).

The spelling of 21035342431 in words is "twenty-one billion, thirty-five million, three hundred forty-two thousand, four hundred thirty-one".