20729697 has 4 divisors (see below), whose sum is σ = 27639600. Its totient is φ = 13819796.

The previous prime is 20729633. The next prime is 20729699. The reversal of 20729697 is 79692702.

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 20729697 - 2⁶ = 20729633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20729699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3454947 + ... + 3454952.

It is an arithmetic number, because the mean of its divisors is an integer number (6909900).

Almost surely, 2^20729697 is an apocalyptic number.

It is an amenable number.

20729697 is a deficient number, since it is larger than the sum of its proper divisors (6909903).

20729697 is an equidigital number, since it uses as much as digits as its factorization.

20729697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6909902.

The product of its (nonzero) digits is 95256, while the sum is 42.

The square root of 20729697 is about 4552.9877004007. The cubic root of 20729697 is about 274.7035792273.

The spelling of 20729697 in words is "twenty million, seven hundred twenty-nine thousand, six hundred ninety-seven".