29681561 has 8 divisors (see below), whose sum is σ = 36531264. Its totient is φ = 23484240.

The previous prime is 29681521. The next prime is 29681573. The reversal of 29681561 is 16518692.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 29681561 - 2¹⁸ = 29419417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (29681501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162995 + ... + 163176.

It is an arithmetic number, because the mean of its divisors is an integer number (4566408).

Almost surely, 2^29681561 is an apocalyptic number.

It is an amenable number.

29681561 is a deficient number, since it is larger than the sum of its proper divisors (6849703).

29681561 is a wasteful number, since it uses less digits than its factorization.

29681561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326191.

The product of its digits is 25920, while the sum is 38.

The square root of 29681561 is about 5448.0786521488. The cubic root of 29681561 is about 309.6199331100.

The spelling of 29681561 in words is "twenty-nine million, six hundred eighty-one thousand, five hundred sixty-one".