20777881236 has 48 divisors (see below), whose sum is σ = 58666962816. Its totient is φ = 5587329024.

The previous prime is 20777881211. The next prime is 20777881237. The reversal of 20777881236 is 63218877702.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20777881237) 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, 7273741 + ... + 7276596.

It is an arithmetic number, because the mean of its divisors is an integer number (1222228392).

Almost surely, 2^20777881236 is an apocalyptic number.

It is an amenable number.

20777881236 is an abundant number, since it is smaller than the sum of its proper divisors (37889081580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20777881236 is a wasteful number, since it uses less digits than its factorization.

20777881236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14550368 (or 14550366 counting only the distinct ones).

The product of its (nonzero) digits is 1580544, while the sum is 51.

The spelling of 20777881236 in words is "twenty billion, seven hundred seventy-seven million, eight hundred eighty-one thousand, two hundred thirty-six".