20391077952 has 252 divisors, whose sum is σ = 68154924396. Its totient is φ = 5811886080.

The previous prime is 20391077933. The next prime is 20391077953. The reversal of 20391077952 is 25977019302.

It can be written as a sum of positive squares in 2 ways, for example, as 18655189056 + 1735888896 = 136584^2 + 41664^2 .

It is a tau number, because it is divible by the number of its divisors (252).

It is a junction number, because it is equal to n+sod(n) for n = 20391077898 and 20391077907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20391077953) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 18655518 + ... + 18656610.

Almost surely, 2^20391077952 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20391077952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34077462198).

20391077952 is an abundant number, since it is smaller than the sum of its proper divisors (47763846444).

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

20391077952 is a wasteful number, since it uses less digits than its factorization.

20391077952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1786 (or 1766 counting only the distinct ones).

The product of its (nonzero) digits is 238140, while the sum is 45.

The spelling of 20391077952 in words is "twenty billion, three hundred ninety-one million, seventy-seven thousand, nine hundred fifty-two".