21435888100 has 81 divisors (see below), whose sum is σ = 51167464873. Its totient is φ = 7794868400.

The previous prime is 21435888053. The next prime is 21435888109. The reversal of 21435888100 is 188853412.

The square root of 21435888100 is 146410.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7716919716 + 13718968384 = 87846^2 + 117128^2 .

It is a super-2 number, since 2×21435888100² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21435888109) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1948717095 + ... + 1948717105.

Almost surely, 2^21435888100 is an apocalyptic number.

21435888100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21435888100 is the 146410-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21435888100

21435888100 is an abundant number, since it is smaller than the sum of its proper divisors (29731576773).

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

21435888100 is an frugal number, since it uses more digits than its factorization.

21435888100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 40.

The spelling of 21435888100 in words is "twenty-one billion, four hundred thirty-five million, eight hundred eighty-eight thousand, one hundred".