21959697312 has 216 divisors, whose sum is σ = 73327415616. Its totient is φ = 6215134464.

The previous prime is 21959697269. The next prime is 21959697313. The reversal of 21959697312 is 21379695912.

21959697312 is a `hidden beast` number, since 2 + 19 + 596 + 9 + 7 + 31 + 2 = 666.

It is not an unprimeable number, because it can be changed into a prime (21959697313) 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, 1502713 + ... + 1517255.

It is an arithmetic number, because the mean of its divisors is an integer number (339478776).

Almost surely, 2^21959697312 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 21959697312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36663707808).

21959697312 is an abundant number, since it is smaller than the sum of its proper divisors (51367718304).

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

21959697312 is a wasteful number, since it uses less digits than its factorization.

21959697312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14680 (or 14662 counting only the distinct ones).

The product of its digits is 1837080, while the sum is 54.

The spelling of 21959697312 in words is "twenty-one billion, nine hundred fifty-nine million, six hundred ninety-seven thousand, three hundred twelve".