21931418861 has 8 divisors (see below), whose sum is σ = 24162068448. Its totient is φ = 19740250000.

The previous prime is 21931418849. The next prime is 21931418911. The reversal of 21931418861 is 16881413912.

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 21931418861 - 2¹⁴ = 21931402477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21931418161) 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, 9869015 + ... + 9871236.

It is an arithmetic number, because the mean of its divisors is an integer number (3020258556).

Almost surely, 2^21931418861 is an apocalyptic number.

It is an amenable number.

21931418861 is a deficient number, since it is larger than the sum of its proper divisors (2230649587).

21931418861 is a wasteful number, since it uses less digits than its factorization.

21931418861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19740363.

The product of its digits is 82944, while the sum is 44.

The spelling of 21931418861 in words is "twenty-one billion, nine hundred thirty-one million, four hundred eighteen thousand, eight hundred sixty-one".