1553042521 has 4 divisors (see below), whose sum is σ = 1555233700. Its totient is φ = 1550851344.

The previous prime is 1553042509. The next prime is 1553042537. The reversal of 1553042521 is 1252403551.

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 58369600 + 1494672921 = 7640^2 + 38661^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553042521 - 2²¹ = 1550945369 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1553042521.

It is not an unprimeable number, because it can be changed into a prime (1553042581) 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, 1094526 + ... + 1095943.

It is an arithmetic number, because the mean of its divisors is an integer number (388808425).

Almost surely, 2^1553042521 is an apocalyptic number.

It is an amenable number.

1553042521 is a deficient number, since it is larger than the sum of its proper divisors (2191179).

1553042521 is an equidigital number, since it uses as much as digits as its factorization.

1553042521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2191178.

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 1553042521 is about 39408.6604821834. The cubic root of 1553042521 is about 1158.0512566265.

The spelling of 1553042521 in words is "one billion, five hundred fifty-three million, forty-two thousand, five hundred twenty-one".