20851679429 has 4 divisors (see below), whose sum is σ = 23830490784. Its totient is φ = 17872868076.

The previous prime is 20851679363. The next prime is 20851679449. The reversal of 20851679429 is 92497615802.

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 not a de Polignac number, because 20851679429 - 2²⁴ = 20834902213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20851679449) 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, 1489405667 + ... + 1489405680.

It is an arithmetic number, because the mean of its divisors is an integer number (5957622696).

Almost surely, 2^20851679429 is an apocalyptic number.

It is an amenable number.

20851679429 is a deficient number, since it is larger than the sum of its proper divisors (2978811355).

20851679429 is an equidigital number, since it uses as much as digits as its factorization.

20851679429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2978811354.

The product of its (nonzero) digits is 2177280, while the sum is 53.

The spelling of 20851679429 in words is "twenty billion, eight hundred fifty-one million, six hundred seventy-nine thousand, four hundred twenty-nine".