15664352421 has 16 divisors (see below), whose sum is σ = 21585904128. Its totient is φ = 10093675200.

The previous prime is 15664352413. The next prime is 15664352479. The reversal of 15664352421 is 12425346651.

15664352421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 15664352421 - 2³ = 15664352413 is a prime.

It is a super-2 number, since 2×15664352421² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 15664352421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15664352411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26226 + ... + 178931.

It is an arithmetic number, because the mean of its divisors is an integer number (1349119008).

Almost surely, 2^15664352421 is an apocalyptic number.

It is an amenable number.

15664352421 is a deficient number, since it is larger than the sum of its proper divisors (5921551707).

15664352421 is a wasteful number, since it uses less digits than its factorization.

15664352421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206012.

The product of its digits is 172800, while the sum is 39.

The spelling of 15664352421 in words is "fifteen billion, six hundred sixty-four million, three hundred fifty-two thousand, four hundred twenty-one".