29972181 has 4 divisors (see below), whose sum is σ = 39962912. Its totient is φ = 19981452.

The previous prime is 29972179. The next prime is 29972191. The reversal of 29972181 is 18127992.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 29972181 - 2¹ = 29972179 is a prime.

It is a super-2 number, since 2×29972181² = 1796663267793522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (29972191) 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, 4995361 + ... + 4995366.

It is an arithmetic number, because the mean of its divisors is an integer number (9990728).

Almost surely, 2^29972181 is an apocalyptic number.

It is an amenable number.

29972181 is a deficient number, since it is larger than the sum of its proper divisors (9990731).

29972181 is an equidigital number, since it uses as much as digits as its factorization.

29972181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9990730.

The product of its digits is 18144, while the sum is 39.

The square root of 29972181 is about 5474.6854704175. The cubic root of 29972181 is about 310.6271763360.

The spelling of 29972181 in words is "twenty-nine million, nine hundred seventy-two thousand, one hundred eighty-one".