146691581 has 2 divisors, whose sum is σ = 146691582. Its totient is φ = 146691580.

The previous prime is 146691577. The next prime is 146691593. The reversal of 146691581 is 185196641.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81631225 + 65060356 = 9035^2 + 8066^2 .

It is a cyclic number.

It is not a de Polignac number, because 146691581 - 2² = 146691577 is a prime.

It is a super-2 number, since 2×146691581² = 43036839872559122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (146691551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 73345790 + 73345791.

It is an arithmetic number, because the mean of its divisors is an integer number (73345791).

Almost surely, 2^146691581 is an apocalyptic number.

It is an amenable number.

146691581 is a deficient number, since it is larger than the sum of its proper divisors (1).

146691581 is an equidigital number, since it uses as much as digits as its factorization.

146691581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 41.

The square root of 146691581 is about 12111.6299893945. The cubic root of 146691581 is about 527.3938523941.

The spelling of 146691581 in words is "one hundred forty-six million, six hundred ninety-one thousand, five hundred eighty-one".