20516429 has 4 divisors (see below), whose sum is σ = 20529180. Its totient is φ = 20503680.

The previous prime is 20516423. The next prime is 20516471. The reversal of 20516429 is 92461502.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8970025 + 11546404 = 2995^2 + 3398^2 .

It is a cyclic number.

It is not a de Polignac number, because 20516429 - 2⁸ = 20516173 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 (20516423) 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, 3542 + ... + 7319.

It is an arithmetic number, because the mean of its divisors is an integer number (5132295).

Almost surely, 2^20516429 is an apocalyptic number.

It is an amenable number.

20516429 is a deficient number, since it is larger than the sum of its proper divisors (12751).

20516429 is a wasteful number, since it uses less digits than its factorization.

20516429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12750.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 20516429 is about 4529.5064852586. The cubic root of 20516429 is about 273.7582759881.

The spelling of 20516429 in words is "twenty million, five hundred sixteen thousand, four hundred twenty-nine".