1261217497 has 2 divisors, whose sum is σ = 1261217498. Its totient is φ = 1261217496.

The previous prime is 1261217459. The next prime is 1261217509. The reversal of 1261217497 is 7947121621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 714172176 + 547045321 = 26724^2 + 23389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261217497 is a prime.

It is not a weakly prime, because it can be changed into another prime (1261217407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630608748 + 630608749.

It is an arithmetic number, because the mean of its divisors is an integer number (630608749).

Almost surely, 2^1261217497 is an apocalyptic number.

It is an amenable number.

1261217497 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261217497 is an equidigital number, since it uses as much as digits as its factorization.

1261217497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 40.

The square root of 1261217497 is about 35513.6241039970. The cubic root of 1261217497 is about 1080.4300690592.

The spelling of 1261217497 in words is "one billion, two hundred sixty-one million, two hundred seventeen thousand, four hundred ninety-seven".