201218931 has 16 divisors (see below), whose sum is σ = 302991520. Its totient is φ = 131945760.

The previous prime is 201218909. The next prime is 201218981. The reversal of 201218931 is 139812102.

It is not a de Polignac number, because 201218931 - 2⁶ = 201218867 is a prime.

It is a super-2 number, since 2×201218931² = 80978116385565522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201218895 and 201218904.

It is not an unprimeable number, because it can be changed into a prime (201218981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59440 + ... + 62733.

It is an arithmetic number, because the mean of its divisors is an integer number (18936970).

Almost surely, 2^201218931 is an apocalyptic number.

201218931 is a deficient number, since it is larger than the sum of its proper divisors (101772589).

201218931 is a wasteful number, since it uses less digits than its factorization.

201218931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122243 (or 122237 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 201218931 is about 14185.1658784802. The cubic root of 201218931 is about 585.9892008012.

The spelling of 201218931 in words is "two hundred one million, two hundred eighteen thousand, nine hundred thirty-one".