61571521 has 4 divisors (see below), whose sum is σ = 67168944. Its totient is φ = 55974100.

The previous prime is 61571513. The next prime is 61571527. The reversal of 61571521 is 12517516.

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 61571521 - 2³ = 61571513 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 61571521.

It is not an unprimeable number, because it can be changed into a prime (61571527) 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, 2798695 + ... + 2798716.

It is an arithmetic number, because the mean of its divisors is an integer number (16792236).

Almost surely, 2^61571521 is an apocalyptic number.

It is an amenable number.

61571521 is a deficient number, since it is larger than the sum of its proper divisors (5597423).

61571521 is a wasteful number, since it uses less digits than its factorization.

61571521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5597422.

The product of its digits is 2100, while the sum is 28.

The square root of 61571521 is about 7846.7522581002. The cubic root of 61571521 is about 394.8752925768.

The spelling of 61571521 in words is "sixty-one million, five hundred seventy-one thousand, five hundred twenty-one".