31400444021 has 4 divisors (see below), whose sum is σ = 31403792832. Its totient is φ = 31397095212.

The previous prime is 31400444003. The next prime is 31400444041. The reversal of 31400444021 is 12044400413.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31400444021 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 (31400444041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1660301 + ... + 1679106.

It is an arithmetic number, because the mean of its divisors is an integer number (7850948208).

Almost surely, 2^31400444021 is an apocalyptic number.

It is an amenable number.

31400444021 is a deficient number, since it is larger than the sum of its proper divisors (3348811).

31400444021 is an equidigital number, since it uses as much as digits as its factorization.

31400444021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3348810.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 31400444021 its reverse (12044400413), we get a palindrome (43444844434).

The spelling of 31400444021 in words is "thirty-one billion, four hundred million, four hundred forty-four thousand, twenty-one".