21145121532 has 36 divisors (see below), whose sum is σ = 53483289496. Its totient is φ = 7044006240.

The previous prime is 21145121443. The next prime is 21145121537. The reversal of 21145121532 is 23512154112.

It is a happy number.

21145121532 is a `hidden beast` number, since 2 + 1 + 1 + 4 + 5 + 121 + 532 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 21145121496 and 21145121505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21145121537) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 122818 + ... + 239529.

Almost surely, 2^21145121532 is an apocalyptic number.

It is an amenable number.

21145121532 is an abundant number, since it is smaller than the sum of its proper divisors (32338167964).

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

21145121532 is a wasteful number, since it uses less digits than its factorization.

21145121532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363978 (or 363973 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

Adding to 21145121532 its reverse (23512154112), we get a palindrome (44657275644).

The spelling of 21145121532 in words is "twenty-one billion, one hundred forty-five million, one hundred twenty-one thousand, five hundred thirty-two".