1261216523 has 32 divisors (see below), whose sum is σ = 1605795840. Its totient is φ = 965653920.

The previous prime is 1261216511. The next prime is 1261216543. The reversal of 1261216523 is 3256121621.

It is not a de Polignac number, because 1261216523 - 2⁸ = 1261216267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261216543) 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, 214286 + ... + 220092.

It is an arithmetic number, because the mean of its divisors is an integer number (50181120).

Almost surely, 2^1261216523 is an apocalyptic number.

1261216523 is a deficient number, since it is larger than the sum of its proper divisors (344579317).

1261216523 is a wasteful number, since it uses less digits than its factorization.

1261216523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5927.

The product of its digits is 4320, while the sum is 29.

The square root of 1261216523 is about 35513.6103909473. The cubic root of 1261216523 is about 1080.4297909314.

The spelling of 1261216523 in words is "one billion, two hundred sixty-one million, two hundred sixteen thousand, five hundred twenty-three".