20749542729 has 8 divisors (see below), whose sum is σ = 29293472160. Its totient is φ = 13019320896.

The previous prime is 20749542727. The next prime is 20749542731. The reversal of 20749542729 is 92724594702.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20749542727) and next prime (20749542731).

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

It is not a de Polignac number, because 20749542729 - 2¹ = 20749542727 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51), and also a Moran number because the ratio is a prime number: 406853779 = 20749542729 / (2 + 0 + 7 + 4 + 9 + 5 + 4 + 2 + 7 + 2 + 9).

It is not an unprimeable number, because it can be changed into a prime (20749542727) 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, 203426839 + ... + 203426940.

It is an arithmetic number, because the mean of its divisors is an integer number (3661684020).

Almost surely, 2^20749542729 is an apocalyptic number.

It is an amenable number.

20749542729 is a deficient number, since it is larger than the sum of its proper divisors (8543929431).

20749542729 is a wasteful number, since it uses less digits than its factorization.

20749542729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406853799.

The product of its (nonzero) digits is 2540160, while the sum is 51.

The spelling of 20749542729 in words is "twenty billion, seven hundred forty-nine million, five hundred forty-two thousand, seven hundred twenty-nine".