61691886 has 12 divisors (see below), whose sum is σ = 133665792. Its totient is φ = 20563956.

The previous prime is 61691881. The next prime is 61691909. The reversal of 61691886 is 68819616.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61691881) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1713646 + ... + 1713681.

It is an arithmetic number, because the mean of its divisors is an integer number (11138816).

Almost surely, 2^61691886 is an apocalyptic number.

61691886 is an abundant number, since it is smaller than the sum of its proper divisors (71973906).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61691886 is a wasteful number, since it uses less digits than its factorization.

61691886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3427335 (or 3427332 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 61691886 is about 7854.4182470760. The cubic root of 61691886 is about 395.1324364973.

The spelling of 61691886 in words is "sixty-one million, six hundred ninety-one thousand, eight hundred eighty-six".