21953091100 has 36 divisors (see below), whose sum is σ = 50440459104. Its totient is φ = 8264692480.

The previous prime is 21953091071. The next prime is 21953091101. The reversal of 21953091100 is 119035912.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21953091101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6455092 + ... + 6458491.

It is an arithmetic number, because the mean of its divisors is an integer number (1401123864).

Almost surely, 2^21953091100 is an apocalyptic number.

21953091100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21953091100 is an abundant number, since it is smaller than the sum of its proper divisors (28487368004).

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

21953091100 is a wasteful number, since it uses less digits than its factorization.

21953091100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12913614 (or 12913607 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 31.

The spelling of 21953091100 in words is "twenty-one billion, nine hundred fifty-three million, ninety-one thousand, one hundred".