1287896961 has 32 divisors (see below), whose sum is σ = 1934811648. Its totient is φ = 756725760.

The previous prime is 1287896957. The next prime is 1287896977. The reversal of 1287896961 is 1696987821.

It is not a de Polignac number, because 1287896961 - 2² = 1287896957 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1287896461) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66585 + ... + 83721.

It is an arithmetic number, because the mean of its divisors is an integer number (60462864).

Almost surely, 2^1287896961 is an apocalyptic number.

It is an amenable number.

1287896961 is a deficient number, since it is larger than the sum of its proper divisors (646914687).

1287896961 is a wasteful number, since it uses less digits than its factorization.

1287896961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17241.

The product of its digits is 2612736, while the sum is 57.

The square root of 1287896961 is about 35887.2813263975. The cubic root of 1287896961 is about 1087.9953506077.

The spelling of 1287896961 in words is "one billion, two hundred eighty-seven million, eight hundred ninety-six thousand, nine hundred sixty-one".