721850745924 has 405 divisors, whose sum is σ = 2416795515981. Its totient is φ = 187187837760.

The previous prime is 721850745901. The next prime is 721850745929. The reversal of 721850745924 is 429547058127.

The square root of 721850745924 is 849618.

It is a perfect power (a square), and thus also a powerful number.

721850745924 is a `hidden beast` number, since 7 + 2 + 1 + 8 + 507 + 45 + 92 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2353220100 + 719497525824 = 48510^2 + 848232^2 .

It is a super-2 number, since 2×721850745924² (a number of 25 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (721850745929) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 1177570242 + ... + 1177570854.

Almost surely, 2^721850745924 is an apocalyptic number.

721850745924 is the 849618-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721850745924

721850745924 is an abundant number, since it is smaller than the sum of its proper divisors (1694944770057).

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

721850745924 is a wasteful number, since it uses less digits than its factorization.

721850745924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1278 (or 636 counting only the distinct ones).

The product of its (nonzero) digits is 5644800, while the sum is 54.

The spelling of 721850745924 in words is "seven hundred twenty-one billion, eight hundred fifty million, seven hundred forty-five thousand, nine hundred twenty-four".