21122142100 has 18 divisors (see below), whose sum is σ = 45835048574. Its totient is φ = 8448856800.

The previous prime is 21122142061. The next prime is 21122142103. The reversal of 21122142100 is 124122112.

It can be written as a sum of positive squares in 3 ways, for example, as 127870864 + 20994271236 = 11308^2 + 144894^2 .

It is a super-2 number, since 2×21122142100² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122142103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105610611 + ... + 105610810.

Almost surely, 2^21122142100 is an apocalyptic number.

21122142100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122142100 is an abundant number, since it is smaller than the sum of its proper divisors (24712906474).

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

21122142100 is a wasteful number, since it uses less digits than its factorization.

21122142100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211221435 (or 211221428 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21122142100 its reverse (124122112), we get a palindrome (21246264212).

The spelling of 21122142100 in words is "twenty-one billion, one hundred twenty-two million, one hundred forty-two thousand, one hundred".