821700064 has 12 divisors (see below), whose sum is σ = 1617722064. Its totient is φ = 410850016.

The previous prime is 821700053. The next prime is 821700067. The reversal of 821700064 is 460007128.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821700067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12839032 + ... + 12839095.

It is an arithmetic number, because the mean of its divisors is an integer number (134810172).

Almost surely, 2^821700064 is an apocalyptic number.

It is an amenable number.

821700064 is a deficient number, since it is larger than the sum of its proper divisors (796022000).

821700064 is a wasteful number, since it uses less digits than its factorization.

821700064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25678137 (or 25678129 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 821700064 is about 28665.3111617509. The cubic root of 821700064 is about 936.6365626244.

The spelling of 821700064 in words is "eight hundred twenty-one million, seven hundred thousand, sixty-four".