21401528 has 8 divisors (see below), whose sum is σ = 40127880. Its totient is φ = 10700760.

The previous prime is 21401473. The next prime is 21401531. The reversal of 21401528 is 82510412.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1337588 + ... + 1337603.

It is an arithmetic number, because the mean of its divisors is an integer number (5015985).

Almost surely, 2^21401528 is an apocalyptic number.

It is an amenable number.

21401528 is a deficient number, since it is larger than the sum of its proper divisors (18726352).

21401528 is a wasteful number, since it uses less digits than its factorization.

21401528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2675197 (or 2675193 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 21401528 is about 4626.1785525420. The cubic root of 21401528 is about 277.6397175383.

The spelling of 21401528 in words is "twenty-one million, four hundred one thousand, five hundred twenty-eight".