31404424021 has 4 divisors (see below), whose sum is σ = 31448718700. Its totient is φ = 31360129344.

The previous prime is 31404424019. The next prime is 31404424081. The reversal of 31404424021 is 12042440413.

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

It can be written as a sum of positive squares in 2 ways, for example, as 4721201521 + 26683222500 = 68711^2 + 163350^2 .

It is a cyclic number.

It is not a de Polignac number, because 31404424021 - 2¹ = 31404424019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31404424081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22146276 + ... + 22147693.

It is an arithmetic number, because the mean of its divisors is an integer number (7862179675).

Almost surely, 2^31404424021 is an apocalyptic number.

It is an amenable number.

31404424021 is a deficient number, since it is larger than the sum of its proper divisors (44294679).

31404424021 is an equidigital number, since it uses as much as digits as its factorization.

31404424021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44294678.

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 31404424021 its reverse (12042440413), we get a palindrome (43446864434).

The spelling of 31404424021 in words is "thirty-one billion, four hundred four million, four hundred twenty-four thousand, twenty-one".