29891985 has 16 divisors (see below), whose sum is σ = 48366720. Its totient is φ = 15762560.

The previous prime is 29891971. The next prime is 29891987. The reversal of 29891985 is 58919892.

It is not a de Polignac number, because 29891985 - 2⁹ = 29891473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (29891987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9861 + ... + 12530.

It is an arithmetic number, because the mean of its divisors is an integer number (3022920).

Almost surely, 2^29891985 is an apocalyptic number.

It is an amenable number.

29891985 is a deficient number, since it is larger than the sum of its proper divisors (18474735).

29891985 is a wasteful number, since it uses less digits than its factorization.

29891985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22488.

The product of its digits is 466560, while the sum is 51.

The square root of 29891985 is about 5467.3563081255. The cubic root of 29891985 is about 310.3498824443.

It can be divided in two parts, 29891 and 985, that added together give a triangular number (30876 = T₂₄₈).

The spelling of 29891985 in words is "twenty-nine million, eight hundred ninety-one thousand, nine hundred eighty-five".