1297447921 has 32 divisors (see below), whose sum is σ = 1657036800. Its totient is φ = 1007067600.

The previous prime is 1297447799. The next prime is 1297447933.

It is a happy number.

1297447921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1297447921 - 2⁹ = 1297447409 is a prime.

It is a super-2 number, since 2×1297447921² = 3366742215414444482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1297447981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1308736 + ... + 1309726.

It is an arithmetic number, because the mean of its divisors is an integer number (51782400).

Almost surely, 2^1297447921 is an apocalyptic number.

1297447921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1297447921 is a deficient number, since it is larger than the sum of its proper divisors (359588879).

1297447921 is an equidigital number, since it uses as much as digits as its factorization.

1297447921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1370 (or 1356 counting only the distinct ones).

The product of its digits is 254016, while the sum is 46.

The square root of 1297447921 is about 36020.1044001819. The cubic root of 1297447921 is about 1090.6782303677.

The spelling of 1297447921 in words is "one billion, two hundred ninety-seven million, four hundred forty-seven thousand, nine hundred twenty-one".