29999981 has 16 divisors (see below), whose sum is σ = 34352640. Its totient is φ = 25932720.

The previous prime is 29999947. The next prime is 29999989. The reversal of 29999981 is 18999992.

It is a de Polignac number, because none of the positive numbers 2^k-29999981 is a prime.

It is a super-2 number, since 2×29999981² = 1799997720000722, 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 (29999989) 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, 71390 + ... + 71808.

It is an arithmetic number, because the mean of its divisors is an integer number (2147040).

Almost surely, 2^29999981 is an apocalyptic number.

It is an amenable number.

29999981 is a deficient number, since it is larger than the sum of its proper divisors (4352659).

29999981 is a wasteful number, since it uses less digits than its factorization.

29999981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736.

The product of its digits is 944784, while the sum is 56.

The square root of 29999981 is about 5477.2238405966. The cubic root of 29999981 is about 310.7231849982.

The spelling of 29999981 in words is "twenty-nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".