21418818663 has 8 divisors (see below), whose sum is σ = 31154645376. Its totient is φ = 12981102200.

The previous prime is 21418818661. The next prime is 21418818677. The reversal of 21418818663 is 36681881412.

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

It is not a de Polignac number, because 21418818663 - 2¹ = 21418818661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21418818661) 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, 324527523 + ... + 324527588.

It is an arithmetic number, because the mean of its divisors is an integer number (3894330672).

Almost surely, 2^21418818663 is an apocalyptic number.

21418818663 is a deficient number, since it is larger than the sum of its proper divisors (9735826713).

21418818663 is a wasteful number, since it uses less digits than its factorization.

21418818663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649055125.

The product of its digits is 442368, while the sum is 48.

The spelling of 21418818663 in words is "twenty-one billion, four hundred eighteen million, eight hundred eighteen thousand, six hundred sixty-three".