781345001 has 2 divisors, whose sum is σ = 781345002. Its totient is φ = 781345000.

The previous prime is 781344979. The next prime is 781345009. The reversal of 781345001 is 100543187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 767290000 + 14055001 = 27700^2 + 3749^2 .

It is a cyclic number.

It is not a de Polignac number, because 781345001 - 2¹⁴ = 781328617 is a prime.

It is a super-3 number, since 3×781345001³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (781345009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390672500 + 390672501.

It is an arithmetic number, because the mean of its divisors is an integer number (390672501).

Almost surely, 2^781345001 is an apocalyptic number.

It is an amenable number.

781345001 is a deficient number, since it is larger than the sum of its proper divisors (1).

781345001 is an equidigital number, since it uses as much as digits as its factorization.

781345001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 781345001 is about 27952.5490966388. The cubic root of 781345001 is about 921.0452050591.

Adding to 781345001 its reverse (100543187), we get a palindrome (881888188).

The spelling of 781345001 in words is "seven hundred eighty-one million, three hundred forty-five thousand, one".