61538161 has 4 divisors (see below), whose sum is σ = 62113392. Its totient is φ = 60962932.

The previous prime is 61538159. The next prime is 61538173. The reversal of 61538161 is 16183516.

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 61538161 - 2¹ = 61538159 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61538101) 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, 287455 + ... + 287668.

It is an arithmetic number, because the mean of its divisors is an integer number (15528348).

Almost surely, 2^61538161 is an apocalyptic number.

It is an amenable number.

61538161 is a deficient number, since it is larger than the sum of its proper divisors (575231).

61538161 is a wasteful number, since it uses less digits than its factorization.

61538161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575230.

The product of its digits is 4320, while the sum is 31.

The square root of 61538161 is about 7844.6262498605. The cubic root of 61538161 is about 394.8039640397.

The spelling of 61538161 in words is "sixty-one million, five hundred thirty-eight thousand, one hundred sixty-one".