31353448021 has 4 divisors (see below), whose sum is σ = 35832512032. Its totient is φ = 26874384012.

The previous prime is 31353448013. The next prime is 31353448057. The reversal of 31353448021 is 12084435313.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12084435313 = 23 ⋅525410231.

It is not a de Polignac number, because 31353448021 - 2³ = 31353448013 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 (31353448921) 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, 2239531995 + ... + 2239532008.

It is an arithmetic number, because the mean of its divisors is an integer number (8958128008).

Almost surely, 2^31353448021 is an apocalyptic number.

It is an amenable number.

31353448021 is a deficient number, since it is larger than the sum of its proper divisors (4479064011).

31353448021 is an equidigital number, since it uses as much as digits as its factorization.

31353448021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4479064010.

The product of its (nonzero) digits is 34560, while the sum is 34.

The spelling of 31353448021 in words is "thirty-one billion, three hundred fifty-three million, four hundred forty-eight thousand, twenty-one".