1277985397 has 8 divisors (see below), whose sum is σ = 1376611040. Its totient is φ = 1179405360.

The previous prime is 1277985361. The next prime is 1277985431. The reversal of 1277985397 is 7935897721.

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 1277985397 - 2¹⁵ = 1277952629 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 (1277985307) 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, 66622 + ... + 83632.

It is an arithmetic number, because the mean of its divisors is an integer number (172076380).

Almost surely, 2^1277985397 is an apocalyptic number.

It is an amenable number.

1277985397 is a deficient number, since it is larger than the sum of its proper divisors (98625643).

1277985397 is a wasteful number, since it uses less digits than its factorization.

1277985397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22803.

The product of its digits is 6667920, while the sum is 58.

The square root of 1277985397 is about 35748.9216200993. The cubic root of 1277985397 is about 1085.1971148313.

The spelling of 1277985397 in words is "one billion, two hundred seventy-seven million, nine hundred eighty-five thousand, three hundred ninety-seven".