18812213521 has 8 divisors (see below), whose sum is σ = 19633798080. Its totient is φ = 17990934192.

The previous prime is 18812213509. The next prime is 18812213573. The reversal of 18812213521 is 12531221881.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18812213521 - 2⁵ = 18812213489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18812213501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54435 + ... + 201463.

It is an arithmetic number, because the mean of its divisors is an integer number (2454224760).

Almost surely, 2^18812213521 is an apocalyptic number.

It is an amenable number.

18812213521 is a deficient number, since it is larger than the sum of its proper divisors (821584559).

18812213521 is a wasteful number, since it uses less digits than its factorization.

18812213521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152615.

The product of its digits is 7680, while the sum is 34.

The spelling of 18812213521 in words is "eighteen billion, eight hundred twelve million, two hundred thirteen thousand, five hundred twenty-one".