201493781 has 4 divisors (see below), whose sum is σ = 201539532. Its totient is φ = 201448032.

The previous prime is 201493771. The next prime is 201493783. The reversal of 201493781 is 187394102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 164891281 + 36602500 = 12841^2 + 6050^2 .

It is a cyclic number.

It is not a de Polignac number, because 201493781 - 2⁶ = 201493717 is a prime.

It is a super-2 number, since 2×201493781² = 81199487563351922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201493783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15470 + ... + 25343.

It is an arithmetic number, because the mean of its divisors is an integer number (50384883).

Almost surely, 2^201493781 is an apocalyptic number.

It is an amenable number.

201493781 is a deficient number, since it is larger than the sum of its proper divisors (45751).

201493781 is an equidigital number, since it uses as much as digits as its factorization.

201493781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45750.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 201493781 is about 14194.8505099561. The cubic root of 201493781 is about 586.2558852115.

The spelling of 201493781 in words is "two hundred one million, four hundred ninety-three thousand, seven hundred eighty-one".