15664054421 has 4 divisors (see below), whose sum is σ = 15776745600. Its totient is φ = 15551363244.

The previous prime is 15664054369. The next prime is 15664054433. The reversal of 15664054421 is 12445046651.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 15664054421 - 2¹⁴ = 15664038037 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15664050421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56345381 + ... + 56345658.

It is an arithmetic number, because the mean of its divisors is an integer number (3944186400).

Almost surely, 2^15664054421 is an apocalyptic number.

It is an amenable number.

15664054421 is a deficient number, since it is larger than the sum of its proper divisors (112691179).

15664054421 is a wasteful number, since it uses less digits than its factorization.

15664054421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112691178.

The product of its (nonzero) digits is 115200, while the sum is 38.

The spelling of 15664054421 in words is "fifteen billion, six hundred sixty-four million, fifty-four thousand, four hundred twenty-one".