21503642 has 8 divisors (see below), whose sum is σ = 32664000. Its totient is φ = 10615644.

The previous prime is 21503621. The next prime is 21503653. The reversal of 21503642 is 24630512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67892 + ... + 68207.

It is an arithmetic number, because the mean of its divisors is an integer number (4083000).

Almost surely, 2^21503642 is an apocalyptic number.

21503642 is a deficient number, since it is larger than the sum of its proper divisors (11160358).

21503642 is a wasteful number, since it uses less digits than its factorization.

21503642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136180.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21503642 is about 4637.2019580777. The cubic root of 21503642 is about 278.0805884058.

The spelling of 21503642 in words is "twenty-one million, five hundred three thousand, six hundred forty-two".