72046721 has 2 divisors, whose sum is σ = 72046722. Its totient is φ = 72046720.

The previous prime is 72046703. The next prime is 72046747. The reversal of 72046721 is 12764027.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40462321 + 31584400 = 6361^2 + 5620^2 .

It is an emirp because it is prime and its reverse (12764027) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72046721 - 2¹⁴ = 72030337 is a prime.

It is not a weakly prime, because it can be changed into another prime (72046771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36023360 + 36023361.

It is an arithmetic number, because the mean of its divisors is an integer number (36023361).

Almost surely, 2^72046721 is an apocalyptic number.

It is an amenable number.

72046721 is a deficient number, since it is larger than the sum of its proper divisors (1).

72046721 is an equidigital number, since it uses as much as digits as its factorization.

72046721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 72046721 is about 8488.0339890931. The cubic root of 72046721 is about 416.1067299650.

The spelling of 72046721 in words is "seventy-two million, forty-six thousand, seven hundred twenty-one".