29991900 has 72 divisors (see below), whose sum is σ = 87338160. Its totient is φ = 7946240.

The previous prime is 29991889. The next prime is 29991917. The reversal of 29991900 is 919992.

It is a happy number.

It is a super-2 number, since 2×29991900² = 1799028131220000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76906 + ... + 77294.

It is an arithmetic number, because the mean of its divisors is an integer number (1213030).

Almost surely, 2^29991900 is an apocalyptic number.

29991900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 29991900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43669080).

29991900 is an abundant number, since it is smaller than the sum of its proper divisors (57346260).

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

29991900 is a wasteful number, since it uses less digits than its factorization.

29991900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663 (or 656 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 39.

The square root of 29991900 is about 5476.4860996811. The cubic root of 29991900 is about 310.6952829856.

The spelling of 29991900 in words is "twenty-nine million, nine hundred ninety-one thousand, nine hundred".