21001528734 has 16 divisors (see below), whose sum is σ = 43451439120. Its totient is φ = 6759112640.

The previous prime is 21001528699. The next prime is 21001528747. The reversal of 21001528734 is 43782510012.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21001528695 and 21001528704.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60349047 + ... + 60349394.

It is an arithmetic number, because the mean of its divisors is an integer number (2715714945).

Almost surely, 2^21001528734 is an apocalyptic number.

21001528734 is an abundant number, since it is smaller than the sum of its proper divisors (22449910386).

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

21001528734 is a wasteful number, since it uses less digits than its factorization.

21001528734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120698475.

The product of its (nonzero) digits is 13440, while the sum is 33.

The spelling of 21001528734 in words is "twenty-one billion, one million, five hundred twenty-eight thousand, seven hundred thirty-four".