55761521 has 4 divisors (see below), whose sum is σ = 55801200. Its totient is φ = 55721844.

The previous prime is 55761491. The next prime is 55761551. The reversal of 55761521 is 12516755.

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: 12516755 = 5 ⋅2503351.

It is an interprime number because it is at equal distance from previous prime (55761491) and next prime (55761551).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55761521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55761551) 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, 17651 + ... + 20568.

It is an arithmetic number, because the mean of its divisors is an integer number (13950300).

Almost surely, 2^55761521 is an apocalyptic number.

It is an amenable number.

55761521 is a deficient number, since it is larger than the sum of its proper divisors (39679).

55761521 is a wasteful number, since it uses less digits than its factorization.

55761521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39678.

The product of its digits is 10500, while the sum is 32.

The square root of 55761521 is about 7467.3637249032. The cubic root of 55761521 is about 382.0423758076.

The spelling of 55761521 in words is "fifty-five million, seven hundred sixty-one thousand, five hundred twenty-one".