1291777968 has 80 divisors (see below), whose sum is σ = 3652814816. Its totient is φ = 390942720.

The previous prime is 1291777933. The next prime is 1291777973. The reversal of 1291777968 is 8697771921.

It is a super-2 number, since 2×1291777968² = 3337380637220418048, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21096 + ... + 55032.

Almost surely, 2^1291777968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1291777968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1826407408).

1291777968 is an abundant number, since it is smaller than the sum of its proper divisors (2361036848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1291777968 is a wasteful number, since it uses less digits than its factorization.

1291777968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34022 (or 34016 counting only the distinct ones).

The product of its digits is 2667168, while the sum is 57.

The square root of 1291777968 is about 35941.3128307801. The cubic root of 1291777968 is about 1089.0871261519.

The spelling of 1291777968 in words is "one billion, two hundred ninety-one million, seven hundred seventy-seven thousand, nine hundred sixty-eight".