72214721 has 2 divisors, whose sum is σ = 72214722. Its totient is φ = 72214720.

The previous prime is 72214711. The next prime is 72214729. The reversal of 72214721 is 12741227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50694400 + 21520321 = 7120^2 + 4639^2 .

It is a cyclic number.

It is not a de Polignac number, because 72214721 - 2¹⁸ = 71952577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72214729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36107360 + 36107361.

It is an arithmetic number, because the mean of its divisors is an integer number (36107361).

Almost surely, 2^72214721 is an apocalyptic number.

It is an amenable number.

72214721 is a deficient number, since it is larger than the sum of its proper divisors (1).

72214721 is an equidigital number, since it uses as much as digits as its factorization.

72214721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1568, while the sum is 26.

The square root of 72214721 is about 8497.9245113145. The cubic root of 72214721 is about 416.4299075916.

Adding to 72214721 its reverse (12741227), we get a palindrome (84955948).

The spelling of 72214721 in words is "seventy-two million, two hundred fourteen thousand, seven hundred twenty-one".