21818231658001 has 3 divisors (see below), whose sum is σ = 21818236329001. Its totient is φ = 21818226987002.

The previous prime is 21818231657983. The next prime is 21818231658023. The reversal of 21818231658001 is 10085613281812.

The square root of 21818231658001 is 4670999.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 21818231658001 - 2²³ = 21818223269393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21818231158001) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2335500 + ... + 7006498.

Almost surely, 2^{21818231658001} is an apocalyptic number.

21818231658001 is the 4670999-th square number.

21818231658001 is the 2335500-th centered octagonal number.

It is an amenable number.

21818231658001 is a deficient number, since it is larger than the sum of its proper divisors (4671000).

21818231658001 is an frugal number, since it uses more digits than its factorization.

21818231658001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9341998 (or 4670999 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 46.

The spelling of 21818231658001 in words is "twenty-one trillion, eight hundred eighteen billion, two hundred thirty-one million, six hundred fifty-eight thousand, one".