61687994 has 8 divisors (see below), whose sum is σ = 93067380. Its totient is φ = 30665536.

The previous prime is 61687987. The next prime is 61687999. The reversal of 61687994 is 49978616.

61687994 = T₂₆ + T₂₇ + ... + T₇₁₇.

It can be written as a sum of positive squares in 2 ways, for example, as 60637369 + 1050625 = 7787^2 + 1025^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (61687999) 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, 88799 + ... + 89490.

Almost surely, 2^61687994 is an apocalyptic number.

61687994 is a deficient number, since it is larger than the sum of its proper divisors (31379386).

61687994 is a wasteful number, since it uses less digits than its factorization.

61687994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178464.

The product of its digits is 653184, while the sum is 50.

The square root of 61687994 is about 7854.1704845260. The cubic root of 61687994 is about 395.1241269886.

The spelling of 61687994 in words is "sixty-one million, six hundred eighty-seven thousand, nine hundred ninety-four".