19145681 has 2 divisors, whose sum is σ = 19145682. Its totient is φ = 19145680.

The previous prime is 19145671. The next prime is 19145701. The reversal of 19145681 is 18654191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15085456 + 4060225 = 3884^2 + 2015^2 .

It is a cyclic number.

It is not a de Polignac number, because 19145681 - 2¹⁸ = 18883537 is a prime.

It is a super-2 number, since 2×19145681² = 733114201907522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19145671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9572840 + 9572841.

It is an arithmetic number, because the mean of its divisors is an integer number (9572841).

Almost surely, 2^19145681 is an apocalyptic number.

It is an amenable number.

19145681 is a deficient number, since it is larger than the sum of its proper divisors (1).

19145681 is an equidigital number, since it uses as much as digits as its factorization.

19145681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 35.

The square root of 19145681 is about 4375.5777904181. The cubic root of 19145681 is about 267.5204211853.

The spelling of 19145681 in words is "nineteen million, one hundred forty-five thousand, six hundred eighty-one".