2168749621 has 2 divisors, whose sum is σ = 2168749622. Its totient is φ = 2168749620.

The previous prime is 2168749613. The next prime is 2168749637. The reversal of 2168749621 is 1269478612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1613628900 + 555120721 = 40170^2 + 23561^2 .

It is a cyclic number.

It is not a de Polignac number, because 2168749621 - 2³ = 2168749613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2168741621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1084374810 + 1084374811.

It is an arithmetic number, because the mean of its divisors is an integer number (1084374811).

Almost surely, 2^2168749621 is an apocalyptic number.

It is an amenable number.

2168749621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2168749621 is an equidigital number, since it uses as much as digits as its factorization.

2168749621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 46.

The square root of 2168749621 is about 46569.8359563355. The cubic root of 2168749621 is about 1294.4038780246.

The spelling of 2168749621 in words is "two billion, one hundred sixty-eight million, seven hundred forty-nine thousand, six hundred twenty-one".