30890781 has 8 divisors (see below), whose sum is σ = 45764160. Its totient is φ = 20593836.

The previous prime is 30890779. The next prime is 30890803. The reversal of 30890781 is 18709803.

It is not a de Polignac number, because 30890781 - 2¹ = 30890779 is a prime.

It is a super-2 number, since 2×30890781² = 1908480701579922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30890281) 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, 572025 + ... + 572078.

It is an arithmetic number, because the mean of its divisors is an integer number (5720520).

Almost surely, 2^30890781 is an apocalyptic number.

It is an amenable number.

30890781 is a deficient number, since it is larger than the sum of its proper divisors (14873379).

30890781 is a wasteful number, since it uses less digits than its factorization.

30890781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1144112 (or 1144106 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 30890781 is about 5557.9475528292. The cubic root of 30890781 is about 313.7687080584.

The spelling of 30890781 in words is "thirty million, eight hundred ninety thousand, seven hundred eighty-one".