30013781 has 16 divisors (see below), whose sum is σ = 35975424. Its totient is φ = 24482304.

The previous prime is 30013757. The next prime is 30013799. The reversal of 30013781 is 18731003.

It is a happy number.

It is not a de Polignac number, because 30013781 - 2¹⁰ = 30012757 is a prime.

It is a super-2 number, since 2×30013781² = 1801654099831922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30013751) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44261 + ... + 44933.

It is an arithmetic number, because the mean of its divisors is an integer number (2248464).

Almost surely, 2^30013781 is an apocalyptic number.

It is an amenable number.

30013781 is a deficient number, since it is larger than the sum of its proper divisors (5961643).

30013781 is a wasteful number, since it uses less digits than its factorization.

30013781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 30013781 is about 5478.4834580384. The cubic root of 30013781 is about 310.7708219465.

Adding to 30013781 its reverse (18731003), we get a palindrome (48744784).

The spelling of 30013781 in words is "thirty million, thirteen thousand, seven hundred eighty-one".