29071981 has 4 divisors (see below), whose sum is σ = 29177212. Its totient is φ = 28966752.

The previous prime is 29071963. The next prime is 29071997. The reversal of 29071981 is 18917092.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5597956 + 23474025 = 2366^2 + 4845^2 .

It is a cyclic number.

It is not a de Polignac number, because 29071981 - 2¹⁹ = 28547693 is a prime.

It is a super-2 number, since 2×29071981² = 1690360158528722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 29071981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (29071901) 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, 52200 + ... + 52753.

It is an arithmetic number, because the mean of its divisors is an integer number (7294303).

Almost surely, 2^29071981 is an apocalyptic number.

It is an amenable number.

29071981 is a deficient number, since it is larger than the sum of its proper divisors (105231).

29071981 is a wasteful number, since it uses less digits than its factorization.

29071981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105230.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 29071981 is about 5391.8439332013. The cubic root of 29071981 is about 307.4856661527.

The spelling of 29071981 in words is "twenty-nine million, seventy-one thousand, nine hundred eighty-one".