61667640 has 48 divisors (see below), whose sum is σ = 200421000. Its totient is φ = 16444608.

The previous prime is 61667591. The next prime is 61667701. The reversal of 61667640 is 4676616.

61667640 is a `hidden beast` number, since 6 + 1 + 6 + 6 + 7 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 61667595 and 61667604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85290 + ... + 86009.

Almost surely, 2^61667640 is an apocalyptic number.

61667640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61667640 is an abundant number, since it is smaller than the sum of its proper divisors (138753360).

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

61667640 is a wasteful number, since it uses less digits than its factorization.

61667640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171316 (or 171309 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 61667640 is about 7852.8746328972. The cubic root of 61667640 is about 395.0806650406.

The spelling of 61667640 in words is "sixty-one million, six hundred sixty-seven thousand, six hundred forty".