21533154225 has 24 divisors (see below), whose sum is σ = 38837981472. Its totient is φ = 10440316800.

The previous prime is 21533154197. The next prime is 21533154259. The reversal of 21533154225 is 52245133512.

It is not a de Polignac number, because 21533154225 - 2⁸ = 21533153969 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

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 23 ways as a sum of consecutive naturals, for example, 13049572 + ... + 13051221.

It is an arithmetic number, because the mean of its divisors is an integer number (1618249228).

Almost surely, 2^21533154225 is an apocalyptic number.

21533154225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21533154225 is a deficient number, since it is larger than the sum of its proper divisors (17304827247).

21533154225 is a wasteful number, since it uses less digits than its factorization.

21533154225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26100817 (or 26100812 counting only the distinct ones).

The product of its digits is 36000, while the sum is 33.

Adding to 21533154225 its reverse (52245133512), we get a palindrome (73778287737).

The spelling of 21533154225 in words is "twenty-one billion, five hundred thirty-three million, one hundred fifty-four thousand, two hundred twenty-five".