1261553 has 4 divisors (see below), whose sum is σ = 1335780. Its totient is φ = 1187328.

The previous prime is 1261549. The next prime is 1261567. The reversal of 1261553 is 3551621.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1151329 + 110224 = 1073^2 + 332^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261553 - 2² = 1261549 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1261523) 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, 37088 + ... + 37121.

It is an arithmetic number, because the mean of its divisors is an integer number (333945).

2^1261553 is an apocalyptic number.

It is an amenable number.

1261553 is a deficient number, since it is larger than the sum of its proper divisors (74227).

1261553 is an equidigital number, since it uses as much as digits as its factorization.

1261553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74226.

The product of its digits is 900, while the sum is 23.

The square root of 1261553 is about 1123.1887641888. The cubic root of 1261553 is about 108.0525864165.

The spelling of 1261553 in words is "one million, two hundred sixty-one thousand, five hundred fifty-three".