21388654 has 8 divisors (see below), whose sum is σ = 36666288. Its totient is φ = 9166560.

The previous prime is 21388651. The next prime is 21388663. The reversal of 21388654 is 45688312.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21388651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 763867 + ... + 763894.

It is an arithmetic number, because the mean of its divisors is an integer number (4583286).

Almost surely, 2^21388654 is an apocalyptic number.

21388654 is a deficient number, since it is larger than the sum of its proper divisors (15277634).

21388654 is a wasteful number, since it uses less digits than its factorization.

21388654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1527770.

The product of its digits is 46080, while the sum is 37.

The square root of 21388654 is about 4624.7869140102. The cubic root of 21388654 is about 277.5840353666.

The spelling of 21388654 in words is "twenty-one million, three hundred eighty-eight thousand, six hundred fifty-four".