53521665 has 16 divisors (see below), whose sum is σ = 85788288. Its totient is φ = 28493696.

The previous prime is 53521619. The next prime is 53521681. The reversal of 53521665 is 56612535.

It is a cyclic number.

It is not a de Polignac number, because 53521665 - 2¹⁴ = 53505281 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6364 + ... + 12146.

It is an arithmetic number, because the mean of its divisors is an integer number (5361768).

Almost surely, 2^53521665 is an apocalyptic number.

It is an amenable number.

53521665 is a deficient number, since it is larger than the sum of its proper divisors (32266623).

53521665 is a wasteful number, since it uses less digits than its factorization.

53521665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6408.

The product of its digits is 27000, while the sum is 33.

The square root of 53521665 is about 7315.8502581723. The cubic root of 53521665 is about 376.8569582600.

The spelling of 53521665 in words is "fifty-three million, five hundred twenty-one thousand, six hundred sixty-five".