2171653021 has 2 divisors, whose sum is σ = 2171653022. Its totient is φ = 2171653020.

The previous prime is 2171653007. The next prime is 2171653067. The reversal of 2171653021 is 1203561712.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2160855225 + 10797796 = 46485^2 + 3286^2 .

It is a cyclic number.

It is not a de Polignac number, because 2171653021 - 2¹⁷ = 2171521949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2171653091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1085826510 + 1085826511.

It is an arithmetic number, because the mean of its divisors is an integer number (1085826511).

Almost surely, 2^2171653021 is an apocalyptic number.

It is an amenable number.

2171653021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2171653021 is an equidigital number, since it uses as much as digits as its factorization.

2171653021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 2171653021 is about 46600.9980687109. The cubic root of 2171653021 is about 1294.9812454860.

The spelling of 2171653021 in words is "two billion, one hundred seventy-one million, six hundred fifty-three thousand, twenty-one".