840249666 has 32 divisors (see below), whose sum is σ = 1869214080. Its totient is φ = 279784368.

The previous prime is 840249649. The next prime is 840249677. The reversal of 840249666 is 666942048.

It is a super-2 number, since 2×840249666² = 1412039002426223112, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46035 + ... + 61641.

It is an arithmetic number, because the mean of its divisors is an integer number (58412940).

Almost surely, 2^840249666 is an apocalyptic number.

840249666 is an abundant number, since it is smaller than the sum of its proper divisors (1028964414).

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

840249666 is a wasteful number, since it uses less digits than its factorization.

840249666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16615 (or 16609 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 840249666 is about 28987.0603200808. The cubic root of 840249666 is about 943.6322667864.

The spelling of 840249666 in words is "eight hundred forty million, two hundred forty-nine thousand, six hundred sixty-six".