1261921552 has 20 divisors (see below), whose sum is σ = 2445525520. Its totient is φ = 630818208.

The previous prime is 1261921547. The next prime is 1261921561. The reversal of 1261921552 is 2551291621.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126043 + ... + 135685.

It is an arithmetic number, because the mean of its divisors is an integer number (122276276).

Almost surely, 2^1261921552 is an apocalyptic number.

It is an amenable number.

1261921552 is a deficient number, since it is larger than the sum of its proper divisors (1183603968).

1261921552 is an equidigital number, since it uses as much as digits as its factorization.

1261921552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17830 (or 17824 counting only the distinct ones).

The product of its digits is 10800, while the sum is 34.

The square root of 1261921552 is about 35523.5351844379. The cubic root of 1261921552 is about 1080.6310760734.

The spelling of 1261921552 in words is "one billion, two hundred sixty-one million, nine hundred twenty-one thousand, five hundred fifty-two".