6611621389 has 2 divisors, whose sum is σ = 6611621390. Its totient is φ = 6611621388.

The previous prime is 6611621309. The next prime is 6611621407. The reversal of 6611621389 is 9831261166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6071058889 + 540562500 = 77917^2 + 23250^2 .

It is a cyclic number.

It is not a de Polignac number, because 6611621389 - 2²³ = 6603232781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6611621309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3305810694 + 3305810695.

It is an arithmetic number, because the mean of its divisors is an integer number (3305810695).

Almost surely, 2^6611621389 is an apocalyptic number.

It is an amenable number.

6611621389 is a deficient number, since it is larger than the sum of its proper divisors (1).

6611621389 is an equidigital number, since it uses as much as digits as its factorization.

6611621389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 43.

The square root of 6611621389 is about 81311.8772935418. The cubic root of 6611621389 is about 1876.8777764389.

The spelling of 6611621389 in words is "six billion, six hundred eleven million, six hundred twenty-one thousand, three hundred eighty-nine".