18316473721 has 32 divisors (see below), whose sum is σ = 23652263936. Its totient is φ = 13794624000.

The previous prime is 18316473709. The next prime is 18316473733. The reversal of 18316473721 is 12737461381.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18316473709) and next prime (18316473733).

It is a cyclic number.

It is not a de Polignac number, because 18316473721 - 2¹⁹ = 18315949433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18316473121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 118861 + ... + 225301.

It is an arithmetic number, because the mean of its divisors is an integer number (739133248).

Almost surely, 2^18316473721 is an apocalyptic number.

It is an amenable number.

18316473721 is a deficient number, since it is larger than the sum of its proper divisors (5335790215).

18316473721 is a wasteful number, since it uses less digits than its factorization.

18316473721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106553.

The product of its digits is 169344, while the sum is 43.

The spelling of 18316473721 in words is "eighteen billion, three hundred sixteen million, four hundred seventy-three thousand, seven hundred twenty-one".