29987920 has 20 divisors (see below), whose sum is σ = 69722100. Its totient is φ = 11995136.

The previous prime is 29987917. The next prime is 29987921. The reversal of 29987920 is 2978992.

It can be written as a sum of positive squares in 2 ways, for example, as 20575296 + 9412624 = 4536^2 + 3068^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (29987921) 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, 187345 + ... + 187504.

It is an arithmetic number, because the mean of its divisors is an integer number (3486105).

Almost surely, 2^29987920 is an apocalyptic number.

29987920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

29987920 is an abundant number, since it is smaller than the sum of its proper divisors (39734180).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

29987920 is a wasteful number, since it uses less digits than its factorization.

29987920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374862 (or 374856 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 29987920 is about 5476.1227159369. The cubic root of 29987920 is about 310.6815390311.

The spelling of 29987920 in words is "twenty-nine million, nine hundred eighty-seven thousand, nine hundred twenty".