61659121 has 4 divisors (see below), whose sum is σ = 63163044. Its totient is φ = 60155200.

The previous prime is 61659109. The next prime is 61659139. The reversal of 61659121 is 12195616.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10336225 + 51322896 = 3215^2 + 7164^2 .

It is not a de Polignac number, because 61659121 - 2²³ = 53270513 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 (61659181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 751900 + ... + 751981.

It is an arithmetic number, because the mean of its divisors is an integer number (15790761).

Almost surely, 2^61659121 is an apocalyptic number.

It is an amenable number.

61659121 is a deficient number, since it is larger than the sum of its proper divisors (1503923).

61659121 is a wasteful number, since it uses less digits than its factorization.

61659121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503922.

The product of its digits is 3240, while the sum is 31.

The square root of 61659121 is about 7852.3322013272. The cubic root of 61659121 is about 395.0624715592.

The spelling of 61659121 in words is "sixty-one million, six hundred fifty-nine thousand, one hundred twenty-one".