21655404442259 has 8 divisors (see below), whose sum is σ = 24760880976480. Its totient is φ = 18552889740096.

The previous prime is 21655404442249. The next prime is 21655404442277. The reversal of 21655404442259 is 95224440455612.

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 21655404442259 - 2²⁰ = 21655403393683 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21655404442259.

It is not an unprimeable number, because it can be changed into a prime (21655404442229) 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, 740442344 + ... + 740471589.

It is an arithmetic number, because the mean of its divisors is an integer number (3095110122060).

Almost surely, 2^{21655404442259} is an apocalyptic number.

21655404442259 is a deficient number, since it is larger than the sum of its proper divisors (3105476534221).

21655404442259 is a wasteful number, since it uses less digits than its factorization.

21655404442259 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1480916029.

The product of its (nonzero) digits is 13824000, while the sum is 53.

The spelling of 21655404442259 in words is "twenty-one trillion, six hundred fifty-five billion, four hundred four million, four hundred forty-two thousand, two hundred fifty-nine".