919252721 has 2 divisors, whose sum is σ = 919252722. Its totient is φ = 919252720.

The previous prime is 919252717. The next prime is 919252757. The reversal of 919252721 is 127252919.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 740656225 + 178596496 = 27215^2 + 13364^2 .

It is an emirp because it is prime and its reverse (127252919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 919252721 - 2² = 919252717 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (919252771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 459626360 + 459626361.

It is an arithmetic number, because the mean of its divisors is an integer number (459626361).

Almost surely, 2^919252721 is an apocalyptic number.

It is an amenable number.

919252721 is a deficient number, since it is larger than the sum of its proper divisors (1).

919252721 is an equidigital number, since it uses as much as digits as its factorization.

919252721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22680, while the sum is 38.

The square root of 919252721 is about 30319.1807442088. The cubic root of 919252721 is about 972.3254232926.

The spelling of 919252721 in words is "nine hundred nineteen million, two hundred fifty-two thousand, seven hundred twenty-one".