145821691 has 2 divisors, whose sum is σ = 145821692. Its totient is φ = 145821690.

The previous prime is 145821677. The next prime is 145821721. The reversal of 145821691 is 196128541.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145821691 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 145821691.

It is not a weakly prime, because it can be changed into another prime (145821601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72910845 + 72910846.

It is an arithmetic number, because the mean of its divisors is an integer number (72910846).

Almost surely, 2^145821691 is an apocalyptic number.

145821691 is a deficient number, since it is larger than the sum of its proper divisors (1).

145821691 is an equidigital number, since it uses as much as digits as its factorization.

145821691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 37.

The square root of 145821691 is about 12075.6652404743. The cubic root of 145821691 is about 526.3492923531.

The spelling of 145821691 in words is "one hundred forty-five million, eight hundred twenty-one thousand, six hundred ninety-one".