31467040721 has 4 divisors (see below), whose sum is σ = 31469164272. Its totient is φ = 31464917172.

The previous prime is 31467040691. The next prime is 31467040729. The reversal of 31467040721 is 12704076413.

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: 12704076413 = 7 ⋅1814868059.

It is a cyclic number.

It is not a de Polignac number, because 31467040721 - 2¹⁰ = 31467039697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31467040729) 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, 1039391 + ... + 1069236.

It is an arithmetic number, because the mean of its divisors is an integer number (7867291068).

Almost surely, 2^31467040721 is an apocalyptic number.

It is an amenable number.

31467040721 is a deficient number, since it is larger than the sum of its proper divisors (2123551).

31467040721 is a wasteful number, since it uses less digits than its factorization.

31467040721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2123550.

The product of its (nonzero) digits is 28224, while the sum is 35.

The spelling of 31467040721 in words is "thirty-one billion, four hundred sixty-seven million, forty thousand, seven hundred twenty-one".