661142866 has 16 divisors (see below), whose sum is σ = 1035384768. Its totient is φ = 316030000.

The previous prime is 661142851. The next prime is 661142887. The reversal of 661142866 is 668241166.

It is a happy number.

661142866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 147336 + ... + 151756.

It is an arithmetic number, because the mean of its divisors is an integer number (64711548).

Almost surely, 2^661142866 is an apocalyptic number.

661142866 is a deficient number, since it is larger than the sum of its proper divisors (374241902).

661142866 is a wasteful number, since it uses less digits than its factorization.

661142866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7697.

The product of its digits is 82944, while the sum is 40.

The square root of 661142866 is about 25712.6985359375. The cubic root of 661142866 is about 871.1610279613.

The spelling of 661142866 in words is "six hundred sixty-one million, one hundred forty-two thousand, eight hundred sixty-six".