20961540512 has 36 divisors (see below), whose sum is σ = 45360738738. Its totient is φ = 9527971200.

The previous prime is 20961540511. The next prime is 20961540539. The reversal of 20961540512 is 21504516902.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 12896782096 + 8064758416 = 113564^2 + 89804^2 .

It is not an unprimeable number, because it can be changed into a prime (20961540511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2702939 + ... + 2710682.

Almost surely, 2^20961540512 is an apocalyptic number.

20961540512 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

20961540512 is an abundant number, since it is smaller than the sum of its proper divisors (24399198226).

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

20961540512 is a wasteful number, since it uses less digits than its factorization.

20961540512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5413653 (or 5413634 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 35.

The spelling of 20961540512 in words is "twenty billion, nine hundred sixty-one million, five hundred forty thousand, five hundred twelve".