61997689 has 4 divisors (see below), whose sum is σ = 66766756. Its totient is φ = 57228624.

The previous prime is 61997687. The next prime is 61997707. The reversal of 61997689 is 98679916.

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 6718464 + 55279225 = 2592^2 + 7435^2 .

It is a cyclic number.

It is not a de Polignac number, because 61997689 - 2¹ = 61997687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61997687) 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, 2384514 + ... + 2384539.

It is an arithmetic number, because the mean of its divisors is an integer number (16691689).

Almost surely, 2^61997689 is an apocalyptic number.

It is an amenable number.

61997689 is a deficient number, since it is larger than the sum of its proper divisors (4769067).

61997689 is a wasteful number, since it uses less digits than its factorization.

61997689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4769066.

The product of its digits is 1469664, while the sum is 55.

The square root of 61997689 is about 7873.8611239976. The cubic root of 61997689 is about 395.7842433330.

The spelling of 61997689 in words is "sixty-one million, nine hundred ninety-seven thousand, six hundred eighty-nine".