20505012988 has 48 divisors (see below), whose sum is σ = 37366318080. Its totient is φ = 9838512000.

The previous prime is 20505012959. The next prime is 20505012989. The reversal of 20505012988 is 88921050502.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 20505012988.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20505012989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2546673 + ... + 2554711.

It is an arithmetic number, because the mean of its divisors is an integer number (778464960).

Almost surely, 2^20505012988 is an apocalyptic number.

It is an amenable number.

20505012988 is a deficient number, since it is larger than the sum of its proper divisors (16861305092).

20505012988 is a wasteful number, since it uses less digits than its factorization.

20505012988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8338 (or 8336 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 40.

It can be divided in two parts, 2050501 and 2988, that added together give a square (2053489 = 1433²).

The spelling of 20505012988 in words is "twenty billion, five hundred five million, twelve thousand, nine hundred eighty-eight".