1261377984 has 28 divisors (see below), whose sum is σ = 3337396424. Its totient is φ = 420459264.

The previous prime is 1261377973. The next prime is 1261378007. The reversal of 1261377984 is 4897731621.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3284647 + ... + 3285030.

Almost surely, 2^1261377984 is an apocalyptic number.

It is an amenable number.

1261377984 is an abundant number, since it is smaller than the sum of its proper divisors (2076018440).

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

1261377984 is an equidigital number, since it uses as much as digits as its factorization.

1261377984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6569692 (or 6569682 counting only the distinct ones).

The product of its digits is 508032, while the sum is 48.

The square root of 1261377984 is about 35515.8835452534. The cubic root of 1261377984 is about 1080.4758945220.

The spelling of 1261377984 in words is "one billion, two hundred sixty-one million, three hundred seventy-seven thousand, nine hundred eighty-four".