1261512988 has 24 divisors (see below), whose sum is σ = 2226823200. Its totient is φ = 625291008.

The previous prime is 1261512979. The next prime is 1261512991. The reversal of 1261512988 is 8892151621.

It is a congruent number.

It is an unprimeable number.

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, 617673 + ... + 619711.

It is an arithmetic number, because the mean of its divisors is an integer number (92784300).

Almost surely, 2^1261512988 is an apocalyptic number.

It is an amenable number.

1261512988 is a deficient number, since it is larger than the sum of its proper divisors (965310212).

1261512988 is a wasteful number, since it uses less digits than its factorization.

1261512988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3309 (or 3307 counting only the distinct ones).

The product of its digits is 69120, while the sum is 43.

The square root of 1261512988 is about 35517.7841088095. The cubic root of 1261512988 is about 1080.5144405581.

The spelling of 1261512988 in words is "one billion, two hundred sixty-one million, five hundred twelve thousand, nine hundred eighty-eight".