72211621 has 2 divisors, whose sum is σ = 72211622. Its totient is φ = 72211620.

The previous prime is 72211589. The next prime is 72211639. The reversal of 72211621 is 12611227.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51408900 + 20802721 = 7170^2 + 4561^2 .

It is a cyclic number.

It is not a de Polignac number, because 72211621 - 2⁵ = 72211589 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72211592 and 72211601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72211021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36105810 + 36105811.

It is an arithmetic number, because the mean of its divisors is an integer number (36105811).

Almost surely, 2^72211621 is an apocalyptic number.

It is an amenable number.

72211621 is a deficient number, since it is larger than the sum of its proper divisors (1).

72211621 is an equidigital number, since it uses as much as digits as its factorization.

72211621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 336, while the sum is 22.

The square root of 72211621 is about 8497.7421118789. The cubic root of 72211621 is about 416.4239487364.

Adding to 72211621 its reverse (12611227), we get a palindrome (84822848).

The spelling of 72211621 in words is "seventy-two million, two hundred eleven thousand, six hundred twenty-one".