21123401454 has 96 divisors (see below), whose sum is σ = 48998476800. Its totient is φ = 6815251872.

The previous prime is 21123401423. The next prime is 21123401461. The reversal of 21123401454 is 45410432112.

21123401454 is a `hidden beast` number, since 211 + 2 + 3 + 401 + 45 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3575467 + ... + 3581369.

It is an arithmetic number, because the mean of its divisors is an integer number (510400800).

Almost surely, 2^21123401454 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123401454, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24499238400).

21123401454 is an abundant number, since it is smaller than the sum of its proper divisors (27875075346).

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

21123401454 is a wasteful number, since it uses less digits than its factorization.

21123401454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6156 (or 6144 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

Adding to 21123401454 its reverse (45410432112), we get a palindrome (66533833566).

The spelling of 21123401454 in words is "twenty-one billion, one hundred twenty-three million, four hundred one thousand, four hundred fifty-four".