1021090997 has 2 divisors, whose sum is σ = 1021090998. Its totient is φ = 1021090996.

The previous prime is 1021090981. The next prime is 1021091023. The reversal of 1021090997 is 7990901201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 755205361 + 265885636 = 27481^2 + 16306^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021090997 - 2⁴ = 1021090981 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1021090997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021090097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510545498 + 510545499.

It is an arithmetic number, because the mean of its divisors is an integer number (510545499).

Almost surely, 2^1021090997 is an apocalyptic number.

It is an amenable number.

1021090997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021090997 is an equidigital number, since it uses as much as digits as its factorization.

1021090997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10206, while the sum is 38.

The square root of 1021090997 is about 31954.5145010842. The cubic root of 1021090997 is about 1006.9814778719.

The spelling of 1021090997 in words is "one billion, twenty-one million, ninety thousand, nine hundred ninety-seven".