29921890 has 16 divisors (see below), whose sum is σ = 54002232. Its totient is φ = 11937024.

The previous prime is 29921867. The next prime is 29921911. The reversal of 29921890 is 9812992.

It can be written as a sum of positive squares in 4 ways, for example, as 25130169 + 4791721 = 5013^2 + 2189^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202 + ... + 7738.

Almost surely, 2^29921890 is an apocalyptic number.

29921890 is a deficient number, since it is larger than the sum of its proper divisors (24080342).

29921890 is a wasteful number, since it uses less digits than its factorization.

29921890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7941.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 29921890 is about 5470.0904928529. The cubic root of 29921890 is about 310.4533429531.

The spelling of 29921890 in words is "twenty-nine million, nine hundred twenty-one thousand, eight hundred ninety".