21255042152 has 32 divisors (see below), whose sum is σ = 41344403400. Its totient is φ = 10231947264.

The previous prime is 21255042073. The next prime is 21255042173. The reversal of 21255042152 is 25124055212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18723543556 + 2531498596 = 136834^2 + 50314^2 .

It is a super-2 number, since 2×21255042152² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47873 + ... + 211664.

Almost surely, 2^21255042152 is an apocalyptic number.

It is an amenable number.

21255042152 is a deficient number, since it is larger than the sum of its proper divisors (20089361248).

21255042152 is a wasteful number, since it uses less digits than its factorization.

21255042152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259925 (or 259921 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 29.

Adding to 21255042152 its reverse (25124055212), we get a palindrome (46379097364).

The spelling of 21255042152 in words is "twenty-one billion, two hundred fifty-five million, forty-two thousand, one hundred fifty-two".