61998157 has 6 divisors (see below), whose sum is σ = 67134282. Its totient is φ = 57228912.

The previous prime is 61998151. The next prime is 61998187. The reversal of 61998157 is 75189916.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1687401 + 60310756 = 1299^2 + 7766^2 .

It is not a de Polignac number, because 61998157 - 2¹⁵ = 61965389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61998151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 183258 + ... + 183595.

It is an arithmetic number, because the mean of its divisors is an integer number (11189047).

Almost surely, 2^61998157 is an apocalyptic number.

It is an amenable number.

61998157 is a deficient number, since it is larger than the sum of its proper divisors (5136125).

61998157 is a wasteful number, since it uses less digits than its factorization.

61998157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 366879 (or 366866 counting only the distinct ones).

The product of its digits is 136080, while the sum is 46.

The square root of 61998157 is about 7873.8908425251. The cubic root of 61998157 is about 395.7852392118.

The spelling of 61998157 in words is "sixty-one million, nine hundred ninety-eight thousand, one hundred fifty-seven".