21761764427 has 8 divisors (see below), whose sum is σ = 23442896400. Its totient is φ = 20081653920.

The previous prime is 21761764421. The next prime is 21761764429. The reversal of 21761764427 is 72446716712.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21761764427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21761764421) 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, 210824 + ... + 296597.

It is an arithmetic number, because the mean of its divisors is an integer number (2930362050).

Almost surely, 2^21761764427 is an apocalyptic number.

21761764427 is a deficient number, since it is larger than the sum of its proper divisors (1681131973).

21761764427 is a wasteful number, since it uses less digits than its factorization.

21761764427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510733.

The product of its digits is 790272, while the sum is 47.

The spelling of 21761764427 in words is "twenty-one billion, seven hundred sixty-one million, seven hundred sixty-four thousand, four hundred twenty-seven".