1257276991 has 8 divisors (see below), whose sum is σ = 1357181280. Its totient is φ = 1161142752.

The previous prime is 1257276989. The next prime is 1257277027. The reversal of 1257276991 is 1996727521.

It is a happy number.

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 1257276991 - 2¹ = 1257276989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1257276091) 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, 941820 + ... + 943153.

It is an arithmetic number, because the mean of its divisors is an integer number (169647660).

Almost surely, 2^1257276991 is an apocalyptic number.

1257276991 is a deficient number, since it is larger than the sum of its proper divisors (99904289).

1257276991 is a wasteful number, since it uses less digits than its factorization.

1257276991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1885025.

The product of its digits is 476280, while the sum is 49.

The square root of 1257276991 is about 35458.1019091547. The cubic root of 1257276991 is about 1079.3036752300.

The spelling of 1257276991 in words is "one billion, two hundred fifty-seven million, two hundred seventy-six thousand, nine hundred ninety-one".