1261231487 has 4 divisors (see below), whose sum is σ = 1261309320. Its totient is φ = 1261153656.

The previous prime is 1261231471. The next prime is 1261231493. The reversal of 1261231487 is 7841321621.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1261231487 - 2⁴ = 1261231471 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261231087) 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, 4412 + ... + 50417.

It is an arithmetic number, because the mean of its divisors is an integer number (315327330).

Almost surely, 2^1261231487 is an apocalyptic number.

1261231487 is a deficient number, since it is larger than the sum of its proper divisors (77833).

1261231487 is an equidigital number, since it uses as much as digits as its factorization.

1261231487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77832.

The product of its digits is 16128, while the sum is 35.

The square root of 1261231487 is about 35513.8210701130. The cubic root of 1261231487 is about 1080.4340639189.

The spelling of 1261231487 in words is "one billion, two hundred sixty-one million, two hundred thirty-one thousand, four hundred eighty-seven".