20961998208 has 256 divisors, whose sum is σ = 62950809600. Its totient is φ = 6866270208.

The previous prime is 20961998203. The next prime is 20961998227. The reversal of 20961998208 is 80289916902.

It is a super-2 number, since 2×20961998208² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20961998203) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71542510 + ... + 71542802.

It is an arithmetic number, because the mean of its divisors is an integer number (245901600).

Almost surely, 2^20961998208 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 20961998208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31475404800).

20961998208 is an abundant number, since it is smaller than the sum of its proper divisors (41988811392).

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

20961998208 is a wasteful number, since it uses less digits than its factorization.

20961998208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606 (or 588 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 20961998208 in words is "twenty billion, nine hundred sixty-one million, nine hundred ninety-eight thousand, two hundred eight".