61689816 has 64 divisors (see below), whose sum is σ = 173340000. Its totient is φ = 20325888.

The previous prime is 61689811. The next prime is 61689847. The reversal of 61689816 is 61898616.

It is a happy number.

It is a super-2 number, since 2×61689816² = 7611266796227712, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61689811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17620 + ... + 20828.

Almost surely, 2^61689816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61689816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86670000).

61689816 is an abundant number, since it is smaller than the sum of its proper divisors (111650184).

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

61689816 is a wasteful number, since it uses less digits than its factorization.

61689816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3313 (or 3303 counting only the distinct ones).

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

The square root of 61689816 is about 7854.2864730031. The cubic root of 61689816 is about 395.1280170436.

The spelling of 61689816 in words is "sixty-one million, six hundred eighty-nine thousand, eight hundred sixteen".