21556056429 has 24 divisors (see below), whose sum is σ = 32153368832. Its totient is φ = 13901751360.

The previous prime is 21556056421. The next prime is 21556056437. The reversal of 21556056429 is 92465065512.

21556056429 is a `hidden beast` number, since 2 + 1 + 5 + 5 + 60 + 564 + 29 = 666.

It is an interprime number because it is at equal distance from previous prime (21556056421) and next prime (21556056437).

It is not a de Polignac number, because 21556056429 - 2³ = 21556056421 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21556056421) 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 23 ways as a sum of consecutive naturals, for example, 783582 + ... + 810624.

Almost surely, 2^21556056429 is an apocalyptic number.

It is an amenable number.

21556056429 is a deficient number, since it is larger than the sum of its proper divisors (10597312403).

21556056429 is a wasteful number, since it uses less digits than its factorization.

21556056429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29937 (or 29934 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 45.

The spelling of 21556056429 in words is "twenty-one billion, five hundred fifty-six million, fifty-six thousand, four hundred twenty-nine".