1225687997 has 4 divisors (see below), whose sum is σ = 1225834140. Its totient is φ = 1225541856.

The previous prime is 1225687993. The next prime is 1225688027. The reversal of 1225687997 is 7997865221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7997865221 = 17207 ⋅464803.

It can be written as a sum of positive squares in 2 ways, for example, as 439782841 + 785905156 = 20971^2 + 28034^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225687997 - 2² = 1225687993 is a prime.

It is a super-2 number, since 2×1225687997² = 3004622131979744018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225687993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59672 + ... + 77537.

It is an arithmetic number, because the mean of its divisors is an integer number (306458535).

Almost surely, 2^1225687997 is an apocalyptic number.

It is an amenable number.

1225687997 is a deficient number, since it is larger than the sum of its proper divisors (146143).

1225687997 is an equidigital number, since it uses as much as digits as its factorization.

1225687997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146142.

The product of its digits is 3810240, while the sum is 56.

The square root of 1225687997 is about 35009.8271489592. The cubic root of 1225687997 is about 1070.1877555053.

The spelling of 1225687997 in words is "one billion, two hundred twenty-five million, six hundred eighty-seven thousand, nine hundred ninety-seven".