661864214 has 32 divisors (see below), whose sum is σ = 1115056800. Its totient is φ = 291997440.

The previous prime is 661864193. The next prime is 661864237. The reversal of 661864214 is 412468166.

Its product of digits (55296) is a multiple of the sum of its prime divisors (2048).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 462452 + ... + 463880.

It is an arithmetic number, because the mean of its divisors is an integer number (34845525).

Almost surely, 2^661864214 is an apocalyptic number.

661864214 is a deficient number, since it is larger than the sum of its proper divisors (453192586).

661864214 is a wasteful number, since it uses less digits than its factorization.

661864214 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2048.

The product of its digits is 55296, while the sum is 38.

The square root of 661864214 is about 25726.7217888327. The cubic root of 661864214 is about 871.4777430976.

The spelling of 661864214 in words is "six hundred sixty-one million, eight hundred sixty-four thousand, two hundred fourteen".