18212137 has 4 divisors (see below), whose sum is σ = 18227536. Its totient is φ = 18196740.

The previous prime is 18212123. The next prime is 18212143. The reversal of 18212137 is 73121281.

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: 73121281 = 31 ⋅2358751.

It is a cyclic number.

It is not a de Polignac number, because 18212137 - 2⁷ = 18212009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18212147) 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, 5763 + ... + 8344.

It is an arithmetic number, because the mean of its divisors is an integer number (4556884).

Almost surely, 2^18212137 is an apocalyptic number.

It is an amenable number.

18212137 is a deficient number, since it is larger than the sum of its proper divisors (15399).

18212137 is a wasteful number, since it uses less digits than its factorization.

18212137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15398.

The product of its digits is 672, while the sum is 25.

The square root of 18212137 is about 4267.5680428085. The cubic root of 18212137 is about 263.0996697029.

It can be divided in two parts, 18 and 212137, that multiplied together give a triangular number (3818466 = T₂₇₆₃).

The spelling of 18212137 in words is "eighteen million, two hundred twelve thousand, one hundred thirty-seven".