21353454140 has 24 divisors (see below), whose sum is σ = 45001846512. Its totient is φ = 8510983040.

The previous prime is 21353454113. The next prime is 21353454179. The reversal of 21353454140 is 4145435312.

It is a junction number, because it is equal to n+sod(n) for n = 21353454097 and 21353454106.

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 7 ways as a sum of consecutive naturals, for example, 1894154 + ... + 1905393.

It is an arithmetic number, because the mean of its divisors is an integer number (1875076938).

Almost surely, 2^21353454140 is an apocalyptic number.

21353454140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21353454140 is an abundant number, since it is smaller than the sum of its proper divisors (23648392372).

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

21353454140 is a wasteful number, since it uses less digits than its factorization.

21353454140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3799837 (or 3799835 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

Adding to 21353454140 its reverse (4145435312), we get a palindrome (25498889452).

The spelling of 21353454140 in words is "twenty-one billion, three hundred fifty-three million, four hundred fifty-four thousand, one hundred forty".