61681869 has 12 divisors (see below), whose sum is σ = 92168700. Its totient is φ = 39703104.

The previous prime is 61681853. The next prime is 61681897. The reversal of 61681869 is 96818616.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 45400644 + 16281225 = 6738^2 + 4035^2 .

It is not a de Polignac number, because 61681869 - 2⁴ = 61681853 is a prime.

It is a super-3 number, since 3×61681869³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61681819) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117904 + ... + 118425.

It is an arithmetic number, because the mean of its divisors is an integer number (7680725).

Almost surely, 2^61681869 is an apocalyptic number.

It is an amenable number.

61681869 is a deficient number, since it is larger than the sum of its proper divisors (30486831).

61681869 is a wasteful number, since it uses less digits than its factorization.

61681869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236364 (or 236361 counting only the distinct ones).

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

The square root of 61681869 is about 7853.7805546119. The cubic root of 61681869 is about 395.1110492662. Note that the first 3 decimals are identical.

The spelling of 61681869 in words is "sixty-one million, six hundred eighty-one thousand, eight hundred sixty-nine".