15556620447 has 24 divisors (see below), whose sum is σ = 23408920080. Its totient is φ = 9946619520.

The previous prime is 15556620433. The next prime is 15556620463. The reversal of 15556620447 is 74402665551.

15556620447 is a `hidden beast` number, since 15 + 5 + 5 + 6 + 620 + 4 + 4 + 7 = 666.

It is not a de Polignac number, because 15556620447 - 2⁶ = 15556620383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15556620467) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 335508 + ... + 379049.

It is an arithmetic number, because the mean of its divisors is an integer number (975371670).

Almost surely, 2^15556620447 is an apocalyptic number.

15556620447 is a deficient number, since it is larger than the sum of its proper divisors (7852299633).

15556620447 is a wasteful number, since it uses less digits than its factorization.

15556620447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714663 (or 714660 counting only the distinct ones).

The product of its (nonzero) digits is 1008000, while the sum is 45.

The spelling of 15556620447 in words is "fifteen billion, five hundred fifty-six million, six hundred twenty thousand, four hundred forty-seven".