30420981 has 8 divisors (see below), whose sum is σ = 45068160. Its totient is φ = 20280636.

The previous prime is 30420977. The next prime is 30420983. The reversal of 30420981 is 18902403.

It is not a de Polignac number, because 30420981 - 2² = 30420977 is a prime.

It is a super-2 number, since 2×30420981² = 1850872170004722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1126703 = 30420981 / (3 + 0 + 4 + 2 + 0 + 9 + 8 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30420983) 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, 563325 + ... + 563378.

It is an arithmetic number, because the mean of its divisors is an integer number (5633520).

Almost surely, 2^30420981 is an apocalyptic number.

It is an amenable number.

30420981 is a deficient number, since it is larger than the sum of its proper divisors (14647179).

30420981 is a wasteful number, since it uses less digits than its factorization.

30420981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1126712 (or 1126706 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 30420981 is about 5515.5218248140. The cubic root of 30420981 is about 312.1699333152.

The spelling of 30420981 in words is "thirty million, four hundred twenty thousand, nine hundred eighty-one".