1287912969 has 24 divisors (see below), whose sum is σ = 2142832640. Its totient is φ = 730150848.

The previous prime is 1287912961. The next prime is 1287912973. The reversal of 1287912969 is 9692197821.

It is not a de Polignac number, because 1287912969 - 2³ = 1287912961 is a prime.

It is a super-2 number, since 2×1287912969² = 3317439631436789922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1287912961) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 72484 + ... + 88485.

Almost surely, 2^1287912969 is an apocalyptic number.

It is an amenable number.

1287912969 is a deficient number, since it is larger than the sum of its proper divisors (854919671).

1287912969 is a wasteful number, since it uses less digits than its factorization.

1287912969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161109 (or 161106 counting only the distinct ones).

The product of its digits is 979776, while the sum is 54.

The square root of 1287912969 is about 35887.5043573665. The cubic root of 1287912969 is about 1087.9998583590. Note that the first 3 decimals are identical.

The spelling of 1287912969 in words is "one billion, two hundred eighty-seven million, nine hundred twelve thousand, nine hundred sixty-nine".