55780521 has 4 divisors (see below), whose sum is σ = 74374032. Its totient is φ = 37187012.

The previous prime is 55780513. The next prime is 55780531. The reversal of 55780521 is 12508755.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 55780521 - 2³ = 55780513 is a prime.

It is a super-2 number, since 2×55780521² = 6222933046062882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55780531) 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, 9296751 + ... + 9296756.

It is an arithmetic number, because the mean of its divisors is an integer number (18593508).

Almost surely, 2^55780521 is an apocalyptic number.

It is an amenable number.

55780521 is a deficient number, since it is larger than the sum of its proper divisors (18593511).

55780521 is a wasteful number, since it uses less digits than its factorization.

55780521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18593510.

The product of its (nonzero) digits is 14000, while the sum is 33.

The square root of 55780521 is about 7468.6358192109. The cubic root of 55780521 is about 382.0857628406.

The spelling of 55780521 in words is "fifty-five million, seven hundred eighty thousand, five hundred twenty-one".