29987278991 has 4 divisors (see below), whose sum is σ = 30324214800. Its totient is φ = 29650343184.

The previous prime is 29987278973. The next prime is 29987279033. The reversal of 29987278991 is 19987278992.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-29987278991 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 (29987278091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168467771 + ... + 168467948.

It is an arithmetic number, because the mean of its divisors is an integer number (7581053700).

Almost surely, 2^29987278991 is an apocalyptic number.

29987278991 is a deficient number, since it is larger than the sum of its proper divisors (336935809).

29987278991 is an equidigital number, since it uses as much as digits as its factorization.

29987278991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336935808.

The product of its digits is 82301184, while the sum is 71.

Subtracting from 29987278991 its reverse (19987278992), we obtain a palindrome (9999999999).

The spelling of 29987278991 in words is "twenty-nine billion, nine hundred eighty-seven million, two hundred seventy-eight thousand, nine hundred ninety-one".