30779813 has 4 divisors (see below), whose sum is σ = 30799308. Its totient is φ = 30760320.

The previous prime is 30779789. The next prime is 30779831. The reversal of 30779813 is 31897703.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31897703 = 2243 ⋅14221.

It can be written as a sum of positive squares in 2 ways, for example, as 12264004 + 18515809 = 3502^2 + 4303^2 .

It is a cyclic number.

It is not a de Polignac number, because 30779813 - 2¹⁴ = 30763429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30779713) 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, 7148 + ... + 10613.

It is an arithmetic number, because the mean of its divisors is an integer number (7699827).

Almost surely, 2^30779813 is an apocalyptic number.

It is an amenable number.

30779813 is a deficient number, since it is larger than the sum of its proper divisors (19495).

30779813 is a wasteful number, since it uses less digits than its factorization.

30779813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19494.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 30779813 is about 5547.9557496433. The cubic root of 30779813 is about 313.3925433852.

The spelling of 30779813 in words is "thirty million, seven hundred seventy-nine thousand, eight hundred thirteen".