31442447021 has 4 divisors (see below), whose sum is σ = 31690025472. Its totient is φ = 31194868572.

The previous prime is 31442447017. The next prime is 31442447033. The reversal of 31442447021 is 12074424413.

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 not a de Polignac number, because 31442447021 - 2² = 31442447017 is a prime.

It is a super-3 number, since 3×31442447021³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31442447041) 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, 123789035 + ... + 123789288.

It is an arithmetic number, because the mean of its divisors is an integer number (7922506368).

Almost surely, 2^31442447021 is an apocalyptic number.

It is an amenable number.

31442447021 is a deficient number, since it is larger than the sum of its proper divisors (247578451).

31442447021 is a wasteful number, since it uses less digits than its factorization.

31442447021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247578450.

The product of its (nonzero) digits is 21504, while the sum is 32.

The spelling of 31442447021 in words is "thirty-one billion, four hundred forty-two million, four hundred forty-seven thousand, twenty-one".