721554966 has 96 divisors (see below), whose sum is σ = 1794514176. Its totient is φ = 215460000.

The previous prime is 721554961. The next prime is 721554979. The reversal of 721554966 is 669455127.

721554966 is a `hidden beast` number, since 7 + 2 + 1 + 554 + 96 + 6 = 666.

It is a super-2 number, since 2×721554966² = 1041283137918522312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721554961) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 378616 + ... + 380516.

It is an arithmetic number, because the mean of its divisors is an integer number (18692856).

Almost surely, 2^721554966 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721554966, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (897257088).

721554966 is an abundant number, since it is smaller than the sum of its proper divisors (1072959210).

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

721554966 is a wasteful number, since it uses less digits than its factorization.

721554966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2000 (or 1988 counting only the distinct ones).

The product of its digits is 453600, while the sum is 45.

The square root of 721554966 is about 26861.7751833344. The cubic root of 721554966 is about 896.9257105621.

The spelling of 721554966 in words is "seven hundred twenty-one million, five hundred fifty-four thousand, nine hundred sixty-six".