72705780 has 144 divisors (see below), whose sum is σ = 265399680. Its totient is φ = 15738624.

The previous prime is 72705779. The next prime is 72705781. The reversal of 72705780 is 8750727.

It is an interprime number because it is at equal distance from previous prime (72705779) and next prime (72705781).

It is a super-2 number, since 2×72705780² = 10572260890816800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72705781) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 22422 + ... + 25458.

Almost surely, 2^72705780 is an apocalyptic number.

72705780 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 72705780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132699840).

72705780 is an abundant number, since it is smaller than the sum of its proper divisors (192693900).

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

72705780 is a wasteful number, since it uses less digits than its factorization.

72705780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3078 (or 3073 counting only the distinct ones).

The product of its (nonzero) digits is 27440, while the sum is 36.

The square root of 72705780 is about 8526.7684382772. The cubic root of 72705780 is about 417.3716817938.

The spelling of 72705780 in words is "seventy-two million, seven hundred five thousand, seven hundred eighty".