661567066 has 8 divisors (see below), whose sum is σ = 1006327584. Its totient is φ = 326124540.

The previous prime is 661567037. The next prime is 661567073. The reversal of 661567066 is 660765166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2329320 + ... + 2329603.

It is an arithmetic number, because the mean of its divisors is an integer number (125790948).

Almost surely, 2^661567066 is an apocalyptic number.

661567066 is a deficient number, since it is larger than the sum of its proper divisors (344760518).

661567066 is a wasteful number, since it uses less digits than its factorization.

661567066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4658996.

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 661567066 is about 25720.9460556955. The cubic root of 661567066 is about 871.3473051486.

The spelling of 661567066 in words is "six hundred sixty-one million, five hundred sixty-seven thousand, sixty-six".