61661550 has 48 divisors (see below), whose sum is σ = 161922672. Its totient is φ = 15475200.

The previous prime is 61661539. The next prime is 61661617. The reversal of 61661550 is 5516616.

It is a super-3 number, since 3×61661550³ (a number of 24 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9541 + ... + 14640.

It is an arithmetic number, because the mean of its divisors is an integer number (3373389).

Almost surely, 2^61661550 is an apocalyptic number.

61661550 is an abundant number, since it is smaller than the sum of its proper divisors (100261122).

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

61661550 is a wasteful number, since it uses less digits than its factorization.

61661550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24213 (or 24208 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 61661550 is about 7852.4868672288. The cubic root of 61661550 is about 395.0676591893.

The spelling of 61661550 in words is "sixty-one million, six hundred sixty-one thousand, five hundred fifty".