21021343031 has 4 divisors (see below), whose sum is σ = 22638369432. Its totient is φ = 19404316632.

The previous prime is 21021343001. The next prime is 21021343033. The reversal of 21021343031 is 13034312012.

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 21021343031 - 2³⁴ = 3841473847 is a prime.

It is a super-2 number, since 2×21021343031² (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 = 21021342994 and 21021343012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021343033) 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, 808513181 + ... + 808513206.

It is an arithmetic number, because the mean of its divisors is an integer number (5659592358).

Almost surely, 2^21021343031 is an apocalyptic number.

21021343031 is a deficient number, since it is larger than the sum of its proper divisors (1617026401).

21021343031 is a wasteful number, since it uses less digits than its factorization.

21021343031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1617026400.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21021343031 its reverse (13034312012), we get a palindrome (34055655043).

The spelling of 21021343031 in words is "twenty-one billion, twenty-one million, three hundred forty-three thousand, thirty-one".