20451929 has 2 divisors, whose sum is σ = 20451930. Its totient is φ = 20451928.

The previous prime is 20451917. The next prime is 20451941. The reversal of 20451929 is 92915402.

It is a balanced prime because it is at equal distance from previous prime (20451917) and next prime (20451941).

It can be written as a sum of positive squares in only one way, i.e., 17977600 + 2474329 = 4240^2 + 1573^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20451929 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20451895 and 20451904.

It is not a weakly prime, because it can be changed into another prime (20451979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10225964 + 10225965.

It is an arithmetic number, because the mean of its divisors is an integer number (10225965).

Almost surely, 2^20451929 is an apocalyptic number.

It is an amenable number.

20451929 is a deficient number, since it is larger than the sum of its proper divisors (1).

20451929 is an equidigital number, since it uses as much as digits as its factorization.

20451929 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 20451929 is about 4522.3808994820. The cubic root of 20451929 is about 273.4710923997.

The spelling of 20451929 in words is "twenty million, four hundred fifty-one thousand, nine hundred twenty-nine".