1553365261 has 4 divisors (see below), whose sum is σ = 1775274592. Its totient is φ = 1331455932.

The previous prime is 1553365249. The next prime is 1553365271. The reversal of 1553365261 is 1625633551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1625633551 = 17 ⋅95625503.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1553365261 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1553365261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1553365201) 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, 110954655 + ... + 110954668.

It is an arithmetic number, because the mean of its divisors is an integer number (443818648).

Almost surely, 2^1553365261 is an apocalyptic number.

It is an amenable number.

1553365261 is a deficient number, since it is larger than the sum of its proper divisors (221909331).

1553365261 is an equidigital number, since it uses as much as digits as its factorization.

1553365261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221909330.

The product of its digits is 81000, while the sum is 37.

The square root of 1553365261 is about 39412.7550546774. The cubic root of 1553365261 is about 1158.1314698361.

The spelling of 1553365261 in words is "one billion, five hundred fifty-three million, three hundred sixty-five thousand, two hundred sixty-one".