30865213 has 4 divisors (see below), whose sum is σ = 30883968. Its totient is φ = 30846460.

The previous prime is 30865189. The next prime is 30865223. The reversal of 30865213 is 31256803.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31256803 = 53 ⋅589751.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30865213 is a prime.

It is a super-2 number, since 2×30865213² = 1905322747070738, 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 (30865223) 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, 6643 + ... + 10288.

It is an arithmetic number, because the mean of its divisors is an integer number (7720992).

Almost surely, 2^30865213 is an apocalyptic number.

It is an amenable number.

30865213 is a deficient number, since it is larger than the sum of its proper divisors (18755).

30865213 is a wasteful number, since it uses less digits than its factorization.

30865213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18754.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 30865213 is about 5555.6469470261. The cubic root of 30865213 is about 313.6821163909.

The spelling of 30865213 in words is "thirty million, eight hundred sixty-five thousand, two hundred thirteen".