745409681 has 2 divisors, whose sum is σ = 745409682. Its totient is φ = 745409680.

The previous prime is 745409669. The next prime is 745409699. The reversal of 745409681 is 186904547.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 626250625 + 119159056 = 25025^2 + 10916^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-745409681 is a prime.

It is a super-2 number, since 2×745409681² = 1111271185057043522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (745409641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 372704840 + 372704841.

It is an arithmetic number, because the mean of its divisors is an integer number (372704841).

Almost surely, 2^745409681 is an apocalyptic number.

It is an amenable number.

745409681 is a deficient number, since it is larger than the sum of its proper divisors (1).

745409681 is an equidigital number, since it uses as much as digits as its factorization.

745409681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 44.

The square root of 745409681 is about 27302.1918717161. The cubic root of 745409681 is about 906.7029100966.

The spelling of 745409681 in words is "seven hundred forty-five million, four hundred nine thousand, six hundred eighty-one".