31045072021 has 4 divisors (see below), whose sum is σ = 32679023200. Its totient is φ = 29411120844.

The previous prime is 31045071979. The next prime is 31045072133. The reversal of 31045072021 is 12027054013.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12027054013 = 13 ⋅925158001.

It is a cyclic number.

It is not a de Polignac number, because 31045072021 - 2³¹ = 28897588373 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 (31045076021) 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, 816975561 + ... + 816975598.

It is an arithmetic number, because the mean of its divisors is an integer number (8169755800).

Almost surely, 2^31045072021 is an apocalyptic number.

It is an amenable number.

31045072021 is a deficient number, since it is larger than the sum of its proper divisors (1633951179).

31045072021 is a wasteful number, since it uses less digits than its factorization.

31045072021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1633951178.

The product of its (nonzero) digits is 1680, while the sum is 25.

The spelling of 31045072021 in words is "thirty-one billion, forty-five million, seventy-two thousand, twenty-one".