30213781 has 8 divisors (see below), whose sum is σ = 34250720. Its totient is φ = 26421552.

The previous prime is 30213779. The next prime is 30213791. The reversal of 30213781 is 18731203.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 30213781 - 2¹ = 30213779 is a prime.

It is a super-2 number, since 2×30213781² = 1825745124631922, 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 (30213791) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60915 + ... + 61408.

It is an arithmetic number, because the mean of its divisors is an integer number (4281340).

Almost surely, 2^30213781 is an apocalyptic number.

It is an amenable number.

30213781 is a deficient number, since it is larger than the sum of its proper divisors (4036939).

30213781 is a wasteful number, since it uses less digits than its factorization.

30213781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122355.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 30213781 is about 5496.7063774591. The cubic root of 30213781 is about 311.4595790686.

Adding to 30213781 its reverse (18731203), we get a palindrome (48944984).

The spelling of 30213781 in words is "thirty million, two hundred thirteen thousand, seven hundred eighty-one".