61550640 has 60 divisors (see below), whose sum is σ = 206709984. Its totient is φ = 16413312.

The previous prime is 61550639. The next prime is 61550651. The reversal of 61550640 is 4605516.

It is a happy number.

61550640 is a `hidden beast` number, since 6 + 15 + 5 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (60).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42024 + ... + 43463.

Almost surely, 2^61550640 is an apocalyptic number.

61550640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61550640 is an abundant number, since it is smaller than the sum of its proper divisors (145159344).

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

61550640 is a wasteful number, since it uses less digits than its factorization.

61550640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85506 (or 85497 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 61550640 is about 7845.4215947902. The cubic root of 61550640 is about 394.8306489758.

The spelling of 61550640 in words is "sixty-one million, five hundred fifty thousand, six hundred forty".