661552066 has 16 divisors (see below), whose sum is σ = 1136955456. Its totient is φ = 282805776.

The previous prime is 661552063. The next prime is 661552153. The reversal of 661552066 is 660255166.

It is a super-2 number, since 2×661552066² = 875302272057736712, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661552063) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53956 + ... + 65071.

It is an arithmetic number, because the mean of its divisors is an integer number (71059716).

Almost surely, 2^661552066 is an apocalyptic number.

661552066 is a deficient number, since it is larger than the sum of its proper divisors (475403390).

661552066 is a wasteful number, since it uses less digits than its factorization.

661552066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119433.

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 661552066 is about 25720.6544629020. The cubic root of 661552066 is about 871.3407196191.

The spelling of 661552066 in words is "six hundred sixty-one million, five hundred fifty-two thousand, sixty-six".