19221641 has 2 divisors, whose sum is σ = 19221642. Its totient is φ = 19221640.

The previous prime is 19221623. The next prime is 19221647. The reversal of 19221641 is 14612291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18524416 + 697225 = 4304^2 + 835^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19221641 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19221641.

It is not a weakly prime, because it can be changed into another prime (19221647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9610820 + 9610821.

It is an arithmetic number, because the mean of its divisors is an integer number (9610821).

Almost surely, 2^19221641 is an apocalyptic number.

It is an amenable number.

19221641 is a deficient number, since it is larger than the sum of its proper divisors (1).

19221641 is an equidigital number, since it uses as much as digits as its factorization.

19221641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 26.

The square root of 19221641 is about 4384.2491945600. The cubic root of 19221641 is about 267.8737478028.

The spelling of 19221641 in words is "nineteen million, two hundred twenty-one thousand, six hundred forty-one".