72720377 has 4 divisors (see below), whose sum is σ = 73140900. Its totient is φ = 72299856.

The previous prime is 72720311. The next prime is 72720409. The reversal of 72720377 is 77302727.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77302727 = 223 ⋅346649.

It can be written as a sum of positive squares in 2 ways, for example, as 45010681 + 27709696 = 6709^2 + 5264^2 .

It is a cyclic number.

It is not a de Polignac number, because 72720377 - 2⁸ = 72720121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72723377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210002 + ... + 210347.

It is an arithmetic number, because the mean of its divisors is an integer number (18285225).

Almost surely, 2^72720377 is an apocalyptic number.

It is an amenable number.

72720377 is a deficient number, since it is larger than the sum of its proper divisors (420523).

72720377 is a wasteful number, since it uses less digits than its factorization.

72720377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420522.

The product of its (nonzero) digits is 28812, while the sum is 35.

The square root of 72720377 is about 8527.6243467920. The cubic root of 72720377 is about 417.3996115621.

The spelling of 72720377 in words is "seventy-two million, seven hundred twenty thousand, three hundred seventy-seven".