29987989 has 4 divisors (see below), whose sum is σ = 30496320. Its totient is φ = 29479660.

The previous prime is 29987987. The next prime is 29988029. The reversal of 29987989 is 98978992.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 29987989 - 2¹ = 29987987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (29987981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 254077 + ... + 254194.

It is an arithmetic number, because the mean of its divisors is an integer number (7624080).

Almost surely, 2^29987989 is an apocalyptic number.

It is an amenable number.

29987989 is a deficient number, since it is larger than the sum of its proper divisors (508331).

29987989 is an equidigital number, since it uses as much as digits as its factorization.

29987989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508330.

The product of its digits is 5878656, while the sum is 61.

The square root of 29987989 is about 5476.1290160112. The cubic root of 29987989 is about 310.6817773160.

It can be divided in two parts, 29987 and 989, that added together give a square (30976 = 176²).

The spelling of 29987989 in words is "twenty-nine million, nine hundred eighty-seven thousand, nine hundred eighty-nine".