2161550421 has 8 divisors (see below), whose sum is σ = 3202296960. Its totient is φ = 1441033596.

The previous prime is 2161550411. The next prime is 2161550441. The reversal of 2161550421 is 1240551612.

2161550421 is a `hidden beast` number, since 2 + 1 + 615 + 5 + 0 + 42 + 1 = 666.

It is not a de Polignac number, because 2161550421 - 2¹⁷ = 2161419349 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 80057423 = 2161550421 / (2 + 1 + 6 + 1 + 5 + 5 + 0 + 4 + 2 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161550411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40028685 + ... + 40028738.

It is an arithmetic number, because the mean of its divisors is an integer number (400287120).

Almost surely, 2^2161550421 is an apocalyptic number.

It is an amenable number.

2161550421 is a deficient number, since it is larger than the sum of its proper divisors (1040746539).

2161550421 is an equidigital number, since it uses as much as digits as its factorization.

2161550421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80057432 (or 80057426 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 2161550421 is about 46492.4770366131. The cubic root of 2161550421 is about 1292.9700253063.

The spelling of 2161550421 in words is "two billion, one hundred sixty-one million, five hundred fifty thousand, four hundred twenty-one".