1261955493 has 24 divisors (see below), whose sum is σ = 1860794208. Its totient is φ = 823840992.

The previous prime is 1261955483. The next prime is 1261955507. The reversal of 1261955493 is 3945591621.

1261955493 is a `hidden beast` number, since 1 + 2 + 6 + 1 + 9 + 554 + 93 = 666.

It is not a de Polignac number, because 1261955493 - 2⁴ = 1261955477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261955473) 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, 277746 + ... + 282252.

It is an arithmetic number, because the mean of its divisors is an integer number (77533092).

Almost surely, 2^1261955493 is an apocalyptic number.

It is an amenable number.

1261955493 is a deficient number, since it is larger than the sum of its proper divisors (598838715).

1261955493 is a wasteful number, since it uses less digits than its factorization.

1261955493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5153 (or 5150 counting only the distinct ones).

The product of its digits is 291600, while the sum is 45.

The square root of 1261955493 is about 35524.0129067649. The cubic root of 1261955493 is about 1080.6407643065.

The spelling of 1261955493 in words is "one billion, two hundred sixty-one million, nine hundred fifty-five thousand, four hundred ninety-three".