1491275987 has 4 divisors (see below), whose sum is σ = 1539381696. Its totient is φ = 1443170280.

The previous prime is 1491275983. The next prime is 1491276011. The reversal of 1491275987 is 7895721941.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1491275987 - 2² = 1491275983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1491275983) 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, 24052808 + ... + 24052869.

It is an arithmetic number, because the mean of its divisors is an integer number (384845424).

Almost surely, 2^1491275987 is an apocalyptic number.

1491275987 is a deficient number, since it is larger than the sum of its proper divisors (48105709).

1491275987 is an equidigital number, since it uses as much as digits as its factorization.

1491275987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48105708.

The product of its digits is 1270080, while the sum is 53.

The square root of 1491275987 is about 38617.0427013773. The cubic root of 1491275987 is about 1142.4907036066.

The spelling of 1491275987 in words is "one billion, four hundred ninety-one million, two hundred seventy-five thousand, nine hundred eighty-seven".