133751813 has 4 divisors (see below), whose sum is σ = 144040428. Its totient is φ = 123463200.

The previous prime is 133751797. The next prime is 133751861. The reversal of 133751813 is 318157331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 318157331 = 107 ⋅2973433.

It can be written as a sum of positive squares in 2 ways, for example, as 58721569 + 75030244 = 7663^2 + 8662^2 .

It is a cyclic number.

It is not a de Polignac number, because 133751813 - 2⁴ = 133751797 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 133751813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133751873) 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, 5144288 + ... + 5144313.

It is an arithmetic number, because the mean of its divisors is an integer number (36010107).

Almost surely, 2^133751813 is an apocalyptic number.

133751813 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

133751813 is a deficient number, since it is larger than the sum of its proper divisors (10288615).

133751813 is a wasteful number, since it uses less digits than its factorization.

133751813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10288614.

The product of its digits is 7560, while the sum is 32.

The square root of 133751813 is about 11565.1118887800. Note that the first 3 decimals coincide. The cubic root of 133751813 is about 511.4068715946.

The spelling of 133751813 in words is "one hundred thirty-three million, seven hundred fifty-one thousand, eight hundred thirteen".