15655630221 has 24 divisors (see below), whose sum is σ = 28193690304. Its totient is φ = 8132794560.

The previous prime is 15655630219. The next prime is 15655630223. The reversal of 15655630221 is 12203655651.

15655630221 is a `hidden beast` number, since 1 + 56 + 556 + 30 + 2 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (15655630219) and next prime (15655630223).

It is not a de Polignac number, because 15655630221 - 2¹ = 15655630219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15655630223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11294856 + ... + 11296241.

It is an arithmetic number, because the mean of its divisors is an integer number (1174737096).

Almost surely, 2^15655630221 is an apocalyptic number.

15655630221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

15655630221 is a deficient number, since it is larger than the sum of its proper divisors (12538060083).

15655630221 is a wasteful number, since it uses less digits than its factorization.

15655630221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22591121 (or 22591118 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The spelling of 15655630221 in words is "fifteen billion, six hundred fifty-five million, six hundred thirty thousand, two hundred twenty-one".