20661751503 has 48 divisors (see below), whose sum is σ = 31064217600. Its totient is φ = 13219588800.

The previous prime is 20661751493. The next prime is 20661751531. The reversal of 20661751503 is 30515716602.

20661751503 is a `hidden beast` number, since 20 + 6 + 61 + 75 + 1 + 503 = 666.

It is not a de Polignac number, because 20661751503 - 2⁵ = 20661751471 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661751553) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31257993 + ... + 31258653.

It is an arithmetic number, because the mean of its divisors is an integer number (647171200).

Almost surely, 2^20661751503 is an apocalyptic number.

20661751503 is a deficient number, since it is larger than the sum of its proper divisors (10402466097).

20661751503 is a wasteful number, since it uses less digits than its factorization.

20661751503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1460 (or 1457 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The spelling of 20661751503 in words is "twenty billion, six hundred sixty-one million, seven hundred fifty-one thousand, five hundred three".