1091170621 has 2 divisors, whose sum is σ = 1091170622. Its totient is φ = 1091170620.

The previous prime is 1091170609. The next prime is 1091170631. The reversal of 1091170621 is 1260711901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 671535396 + 419635225 = 25914^2 + 20485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1091170621 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1091170621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1091170631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545585310 + 545585311.

It is an arithmetic number, because the mean of its divisors is an integer number (545585311).

Almost surely, 2^1091170621 is an apocalyptic number.

It is an amenable number.

1091170621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091170621 is an equidigital number, since it uses as much as digits as its factorization.

1091170621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 28.

The square root of 1091170621 is about 33032.8718248959. The cubic root of 1091170621 is about 1029.5107554888.

The spelling of 1091170621 in words is "one billion, ninety-one million, one hundred seventy thousand, six hundred twenty-one".