1297777921 has 8 divisors (see below), whose sum is σ = 1477312704. Its totient is φ = 1128502320.

The previous prime is 1297777907. The next prime is 1297777933.

It is a happy number.

1297777921 is nontrivially palindromic in base 10.

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

It is not a de Polignac number, because 1297777921 - 2¹¹ = 1297775873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1297777991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2564526 + ... + 2565031.

It is an arithmetic number, because the mean of its divisors is an integer number (184664088).

Almost surely, 2^1297777921 is an apocalyptic number.

1297777921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1297777921 is a deficient number, since it is larger than the sum of its proper divisors (179534783).

1297777921 is a wasteful number, since it uses less digits than its factorization.

1297777921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5129591.

The product of its digits is 777924, while the sum is 52.

The square root of 1297777921 is about 36024.6848841180. The cubic root of 1297777921 is about 1090.7706922178.

The spelling of 1297777921 in words is "one billion, two hundred ninety-seven million, seven hundred seventy-seven thousand, nine hundred twenty-one".