156621644221 has 16 divisors (see below), whose sum is σ = 181683336960. Its totient is φ = 132235205760.

The previous prime is 156621644209. The next prime is 156621644293. The reversal of 156621644221 is 122446126651.

156621644221 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 156621644221 - 2³⁷ = 19182690749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156621644821) 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 15 ways as a sum of consecutive naturals, for example, 401575 + ... + 688843.

It is an arithmetic number, because the mean of its divisors is an integer number (11355208560).

Almost surely, 2^156621644221 is an apocalyptic number.

It is an amenable number.

156621644221 is a deficient number, since it is larger than the sum of its proper divisors (25061692739).

156621644221 is a wasteful number, since it uses less digits than its factorization.

156621644221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288444.

The product of its digits is 138240, while the sum is 40.

The spelling of 156621644221 in words is "one hundred fifty-six billion, six hundred twenty-one million, six hundred forty-four thousand, two hundred twenty-one".