661241550 has 24 divisors (see below), whose sum is σ = 1639879416. Its totient is φ = 176331040.

The previous prime is 661241509. The next prime is 661241561. The reversal of 661241550 is 55142166.

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 pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2203989 + ... + 2204288.

It is an arithmetic number, because the mean of its divisors is an integer number (68328309).

Almost surely, 2^661241550 is an apocalyptic number.

661241550 is an abundant number, since it is smaller than the sum of its proper divisors (978637866).

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

661241550 is a wasteful number, since it uses less digits than its factorization.

661241550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4408292 (or 4408287 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 661241550 is about 25714.6174383365. The cubic root of 661241550 is about 871.2043697675.

The spelling of 661241550 in words is "six hundred sixty-one million, two hundred forty-one thousand, five hundred fifty".