20515423 has 8 divisors (see below), whose sum is σ = 20832480. Its totient is φ = 20200800.

The previous prime is 20515393. The next prime is 20515463. The reversal of 20515423 is 32451502.

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

It is a cyclic number.

It is not a de Polignac number, because 20515423 - 2⁹ = 20514911 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20515394 and 20515403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20515463) 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 7 ways as a sum of consecutive naturals, for example, 22686 + ... + 23572.

It is an arithmetic number, because the mean of its divisors is an integer number (2604060).

Almost surely, 2^20515423 is an apocalyptic number.

20515423 is a deficient number, since it is larger than the sum of its proper divisors (317057).

20515423 is a wasteful number, since it uses less digits than its factorization.

20515423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1217.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 20515423 is about 4529.3954342716. The cubic root of 20515423 is about 273.7538014387.

Adding to 20515423 its reverse (32451502), we get a palindrome (52966925).

The spelling of 20515423 in words is "twenty million, five hundred fifteen thousand, four hundred twenty-three".