21651068 has 12 divisors (see below), whose sum is σ = 38913672. Its totient is φ = 10532880.

The previous prime is 21651043. The next prime is 21651101. The reversal of 21651068 is 86015612.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21651068.

It is a congruent number.

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, 72998 + ... + 73293.

It is an arithmetic number, because the mean of its divisors is an integer number (3242806).

Almost surely, 2^21651068 is an apocalyptic number.

It is an amenable number.

21651068 is a deficient number, since it is larger than the sum of its proper divisors (17262604).

21651068 is a wasteful number, since it uses less digits than its factorization.

21651068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146332 (or 146330 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 21651068 is about 4653.0708139894. The cubic root of 21651068 is about 278.7146356632.

The spelling of 21651068 in words is "twenty-one million, six hundred fifty-one thousand, sixty-eight".