29997979855561 has 4 divisors (see below), whose sum is σ = 30001967365392. Its totient is φ = 29993992345732.

The previous prime is 29997979855553. The next prime is 29997979855573. The reversal of 29997979855561 is 16555897979992.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 29997979855561 - 2³ = 29997979855553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (29997979856561) 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, 1993743631 + ... + 1993758676.

It is an arithmetic number, because the mean of its divisors is an integer number (7500491841348).

Almost surely, 2^{29997979855561} is an apocalyptic number.

It is an amenable number.

29997979855561 is a deficient number, since it is larger than the sum of its proper divisors (3987509831).

29997979855561 is an equidigital number, since it uses as much as digits as its factorization.

29997979855561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3987509830.

The product of its digits is 34720812000, while the sum is 91.

The spelling of 29997979855561 in words is "twenty-nine trillion, nine hundred ninety-seven billion, nine hundred seventy-nine million, eight hundred fifty-five thousand, five hundred sixty-one".