21918456601 has 8 divisors (see below), whose sum is σ = 23106977600. Its totient is φ = 20733427440.

The previous prime is 21918456587. The next prime is 21918456611. The reversal of 21918456601 is 10665481912.

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 21918456601 - 2⁵ = 21918456569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21918456611) 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, 860061 + ... + 885178.

It is an arithmetic number, because the mean of its divisors is an integer number (2888372200).

Almost surely, 2^21918456601 is an apocalyptic number.

It is an amenable number.

21918456601 is a deficient number, since it is larger than the sum of its proper divisors (1188520999).

21918456601 is a wasteful number, since it uses less digits than its factorization.

21918456601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1745919.

The product of its (nonzero) digits is 103680, while the sum is 43.

The spelling of 21918456601 in words is "twenty-one billion, nine hundred eighteen million, four hundred fifty-six thousand, six hundred one".