72021331 has 2 divisors, whose sum is σ = 72021332. Its totient is φ = 72021330.

The previous prime is 72021283. The next prime is 72021347. The reversal of 72021331 is 13312027.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72021331 is a prime.

It is a super-2 number, since 2×72021331² = 10374144238023122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 72021299 and 72021308.

It is not a weakly prime, because it can be changed into another prime (72021361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36010665 + 36010666.

It is an arithmetic number, because the mean of its divisors is an integer number (36010666).

Almost surely, 2^72021331 is an apocalyptic number.

72021331 is a deficient number, since it is larger than the sum of its proper divisors (1).

72021331 is an equidigital number, since it uses as much as digits as its factorization.

72021331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 72021331 is about 8486.5382223849. The cubic root of 72021331 is about 416.0578441354.

Adding to 72021331 its reverse (13312027), we get a palindrome (85333358).

The spelling of 72021331 in words is "seventy-two million, twenty-one thousand, three hundred thirty-one".