72620221 has 2 divisors, whose sum is σ = 72620222. Its totient is φ = 72620220.

The previous prime is 72620201. The next prime is 72620227. The reversal of 72620221 is 12202627.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70324996 + 2295225 = 8386^2 + 1515^2 .

It is a cyclic number.

It is not a de Polignac number, because 72620221 - 2⁵ = 72620189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72620192 and 72620201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72620227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36310110 + 36310111.

It is an arithmetic number, because the mean of its divisors is an integer number (36310111).

Almost surely, 2^72620221 is an apocalyptic number.

It is an amenable number.

72620221 is a deficient number, since it is larger than the sum of its proper divisors (1).

72620221 is an equidigital number, since it uses as much as digits as its factorization.

72620221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 72620221 is about 8521.7498789861. The cubic root of 72620221 is about 417.2078987562.

Adding to 72620221 its reverse (12202627), we get a palindrome (84822848).

The spelling of 72620221 in words is "seventy-two million, six hundred twenty thousand, two hundred twenty-one".