2165167421 has 2 divisors, whose sum is σ = 2165167422. Its totient is φ = 2165167420.

The previous prime is 2165167393. The next prime is 2165167451. The reversal of 2165167421 is 1247615612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1172035225 + 993132196 = 34235^2 + 31514^2 .

It is a cyclic number.

It is not a de Polignac number, because 2165167421 - 2³⁰ = 1091425597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2165167451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1082583710 + 1082583711.

It is an arithmetic number, because the mean of its divisors is an integer number (1082583711).

Almost surely, 2^2165167421 is an apocalyptic number.

It is an amenable number.

2165167421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2165167421 is an equidigital number, since it uses as much as digits as its factorization.

2165167421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 35.

The square root of 2165167421 is about 46531.3595438603. The cubic root of 2165167421 is about 1293.6908144846.

The spelling of 2165167421 in words is "two billion, one hundred sixty-five million, one hundred sixty-seven thousand, four hundred twenty-one".