721344400 has 180 divisors, whose sum is σ = 2074714432. Its totient is φ = 236079360.

The previous prime is 721344397. The next prime is 721344409. The reversal of 721344400 is 4443127.

It is a super-2 number, since 2×721344400² = 1040675486822720000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721344409) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1480957 + ... + 1481443.

Almost surely, 2^721344400 is an apocalyptic number.

721344400 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721344400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1037357216).

721344400 is an abundant number, since it is smaller than the sum of its proper divisors (1353370032).

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

721344400 is a wasteful number, since it uses less digits than its factorization.

721344400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 558 (or 524 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 721344400 is about 26857.8554616708. The cubic root of 721344400 is about 896.8384543620.

Adding to 721344400 its reverse (4443127), we get a palindrome (725787527).

The spelling of 721344400 in words is "seven hundred twenty-one million, three hundred forty-four thousand, four hundred".