20510423203451 has 4 divisors (see below), whose sum is σ = 20510434661904. Its totient is φ = 20510411745000.

The previous prime is 20510423203429. The next prime is 20510423203507. The reversal of 20510423203451 is 15430232401502.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20510423203451 is a prime.

It is a super-2 number, since 2×20510423203451² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20510423203411) 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, 2399000 + ... + 6839301.

It is an arithmetic number, because the mean of its divisors is an integer number (5127608665476).

Almost surely, 2^{20510423203451} is an apocalyptic number.

20510423203451 is a deficient number, since it is larger than the sum of its proper divisors (11458453).

20510423203451 is an equidigital number, since it uses as much as digits as its factorization.

20510423203451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11458452.

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 20510423203451 its reverse (15430232401502), we get a palindrome (35940655604953).

The spelling of 20510423203451 in words is "twenty trillion, five hundred ten billion, four hundred twenty-three million, two hundred three thousand, four hundred fifty-one".