1217251897 has 2 divisors, whose sum is σ = 1217251898. Its totient is φ = 1217251896.

The previous prime is 1217251873. The next prime is 1217251939. The reversal of 1217251897 is 7981527121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 773896761 + 443355136 = 27819^2 + 21056^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1217251897 is a prime.

It is not a weakly prime, because it can be changed into another prime (1217251097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 608625948 + 608625949.

It is an arithmetic number, because the mean of its divisors is an integer number (608625949).

Almost surely, 2^1217251897 is an apocalyptic number.

It is an amenable number.

1217251897 is a deficient number, since it is larger than the sum of its proper divisors (1).

1217251897 is an equidigital number, since it uses as much as digits as its factorization.

1217251897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70560, while the sum is 43.

The square root of 1217251897 is about 34889.1372349618. The cubic root of 1217251897 is about 1067.7268237740.

The spelling of 1217251897 in words is "one billion, two hundred seventeen million, two hundred fifty-one thousand, eight hundred ninety-seven".