72820720 has 80 divisors (see below), whose sum is σ = 195433920. Its totient is φ = 24717312.

The previous prime is 72820661. The next prime is 72820729. The reversal of 72820720 is 2702827.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×72820720² = 10605714522636800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72820729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60444 + ... + 61636.

It is an arithmetic number, because the mean of its divisors is an integer number (2442924).

Almost surely, 2^72820720 is an apocalyptic number.

72820720 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 72820720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97716960).

72820720 is an abundant number, since it is smaller than the sum of its proper divisors (122613200).

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

72820720 is a wasteful number, since it uses less digits than its factorization.

72820720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1322 (or 1316 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 28.

The square root of 72820720 is about 8533.5057274253. The cubic root of 72820720 is about 417.5915058728.

The spelling of 72820720 in words is "seventy-two million, eight hundred twenty thousand, seven hundred twenty".