1291887804 has 12 divisors (see below), whose sum is σ = 3014404904. Its totient is φ = 430629264.

The previous prime is 1291887803. The next prime is 1291887811. The reversal of 1291887804 is 4087881921.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1291887803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53828647 + ... + 53828670.

Almost surely, 2^1291887804 is an apocalyptic number.

It is an amenable number.

1291887804 is an abundant number, since it is smaller than the sum of its proper divisors (1722517100).

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

1291887804 is a wasteful number, since it uses less digits than its factorization.

1291887804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107657324 (or 107657322 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 48.

The square root of 1291887804 is about 35942.8407892309. The cubic root of 1291887804 is about 1089.1179925460.

The spelling of 1291887804 in words is "one billion, two hundred ninety-one million, eight hundred eighty-seven thousand, eight hundred four".