1297390721 has 8 divisors (see below), whose sum is σ = 1415597664. Its totient is φ = 1179227520.

The previous prime is 1297390709. The next prime is 1297390727. The reversal of 1297390721 is 1270937921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1297390721 - 2²² = 1293196417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1297390727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100586 + ... + 112748.

It is an arithmetic number, because the mean of its divisors is an integer number (176949708).

Almost surely, 2^1297390721 is an apocalyptic number.

1297390721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1297390721 is a deficient number, since it is larger than the sum of its proper divisors (118206943).

1297390721 is a wasteful number, since it uses less digits than its factorization.

1297390721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21871.

The product of its (nonzero) digits is 47628, while the sum is 41.

The square root of 1297390721 is about 36019.3103904003. The cubic root of 1297390721 is about 1090.6622020528.

The spelling of 1297390721 in words is "one billion, two hundred ninety-seven million, three hundred ninety thousand, seven hundred twenty-one".