866419921 has 8 divisors (see below), whose sum is σ = 902842920. Its totient is φ = 830433408.

The previous prime is 866419907. The next prime is 866419933. The reversal of 866419921 is 129914668.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 322597521 + 543822400 = 17961^2 + 23320^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 866419921 - 2⁵ = 866419889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (866410921) 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 7 ways as a sum of consecutive naturals, for example, 105066 + ... + 113011.

It is an arithmetic number, because the mean of its divisors is an integer number (112855365).

Almost surely, 2^866419921 is an apocalyptic number.

It is an amenable number.

866419921 is a deficient number, since it is larger than the sum of its proper divisors (36422999).

866419921 is a wasteful number, since it uses less digits than its factorization.

866419921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218243.

The product of its digits is 186624, while the sum is 46.

The square root of 866419921 is about 29435.0118226577. The cubic root of 866419921 is about 953.3290118174.

The spelling of 866419921 in words is "eight hundred sixty-six million, four hundred nineteen thousand, nine hundred twenty-one".