20887756478 has 8 divisors (see below), whose sum is σ = 31334746320. Its totient is φ = 10442841040.

The previous prime is 20887756471. The next prime is 20887756517. The reversal of 20887756478 is 87465778802.

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

It is a self number, because there is not a number n which added to its sum of digits gives 20887756478.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20887756471) 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, 493178 + ... + 533853.

It is an arithmetic number, because the mean of its divisors is an integer number (3916843290).

Almost surely, 2^20887756478 is an apocalyptic number.

20887756478 is a deficient number, since it is larger than the sum of its proper divisors (10446989842).

20887756478 is a wasteful number, since it uses less digits than its factorization.

20887756478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1037202.

The product of its (nonzero) digits is 42147840, while the sum is 62.

The spelling of 20887756478 in words is "twenty billion, eight hundred eighty-seven million, seven hundred fifty-six thousand, four hundred seventy-eight".