690661986 has 32 divisors (see below), whose sum is σ = 1647295488. Its totient is φ = 188752080.

The previous prime is 690661981. The next prime is 690661987. The reversal of 690661986 is 689166096.

It is not an unprimeable number, because it can be changed into a prime (690661981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 356520 + ... + 358451.

It is an arithmetic number, because the mean of its divisors is an integer number (51477984).

Almost surely, 2^690661986 is an apocalyptic number.

690661986 is an abundant number, since it is smaller than the sum of its proper divisors (956633502).

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

690661986 is a wasteful number, since it uses less digits than its factorization.

690661986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 715006.

The product of its (nonzero) digits is 839808, while the sum is 51.

The square root of 690661986 is about 26280.4487404610. The cubic root of 690661986 is about 883.9380949736.

The spelling of 690661986 in words is "six hundred ninety million, six hundred sixty-one thousand, nine hundred eighty-six".