66121550 has 48 divisors (see below), whose sum is σ = 140026752. Its totient is φ = 22994400.

The previous prime is 66121547. The next prime is 66121567. The reversal of 66121550 is 5512166.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10037 + ... + 15263.

It is an arithmetic number, because the mean of its divisors is an integer number (2917224).

Almost surely, 2^66121550 is an apocalyptic number.

66121550 is an abundant number, since it is smaller than the sum of its proper divisors (73905202).

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

66121550 is a wasteful number, since it uses less digits than its factorization.

66121550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5273 (or 5268 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 66121550 is about 8131.5158488439. The cubic root of 66121550 is about 404.3719371545.

The spelling of 66121550 in words is "sixty-six million, one hundred twenty-one thousand, five hundred fifty".