20451442513 has 8 divisors (see below), whose sum is σ = 20561326632. Its totient is φ = 20341620096.

The previous prime is 20451442441. The next prime is 20451442523. The reversal of 20451442513 is 31524415402.

It can be written as a sum of positive squares in 4 ways, for example, as 2936772864 + 17514669649 = 54192^2 + 132343^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20451442513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20451442523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 750381 + ... + 777157.

It is an arithmetic number, because the mean of its divisors is an integer number (2570165829).

Almost surely, 2^20451442513 is an apocalyptic number.

It is an amenable number.

20451442513 is a deficient number, since it is larger than the sum of its proper divisors (109884119).

20451442513 is a wasteful number, since it uses less digits than its factorization.

20451442513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30851.

The product of its (nonzero) digits is 19200, while the sum is 31.

Adding to 20451442513 its reverse (31524415402), we get a palindrome (51975857915).

The spelling of 20451442513 in words is "twenty billion, four hundred fifty-one million, four hundred forty-two thousand, five hundred thirteen".