21915579047 has 8 divisors (see below), whose sum is σ = 22709111040. Its totient is φ = 21134950200.

The previous prime is 21915578999. The next prime is 21915579061. The reversal of 21915579047 is 74097551912.

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 21915579047 - 2⁶ = 21915578983 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21915578986 and 21915579004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21915579347) 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, 3222329 + ... + 3229122.

It is an arithmetic number, because the mean of its divisors is an integer number (2838638880).

Almost surely, 2^21915579047 is an apocalyptic number.

21915579047 is a deficient number, since it is larger than the sum of its proper divisors (793531993).

21915579047 is an equidigital number, since it uses as much as digits as its factorization.

21915579047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6451573.

The product of its (nonzero) digits is 793800, while the sum is 50.

The spelling of 21915579047 in words is "twenty-one billion, nine hundred fifteen million, five hundred seventy-nine thousand, forty-seven".