21529501828 has 12 divisors (see below), whose sum is σ = 39892900572. Its totient is φ = 10131530240.

The previous prime is 21529501817. The next prime is 21529501837. The reversal of 21529501828 is 82810592512.

It can be written as a sum of positive squares in 2 ways, for example, as 19617363844 + 1912137984 = 140062^2 + 43728^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158305093 + ... + 158305228.

It is an arithmetic number, because the mean of its divisors is an integer number (3324408381).

Almost surely, 2^21529501828 is an apocalyptic number.

It is an amenable number.

21529501828 is a deficient number, since it is larger than the sum of its proper divisors (18363398744).

21529501828 is a wasteful number, since it uses less digits than its factorization.

21529501828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316610342 (or 316610340 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 43.

The spelling of 21529501828 in words is "twenty-one billion, five hundred twenty-nine million, five hundred one thousand, eight hundred twenty-eight".