21436654 has 4 divisors (see below), whose sum is σ = 32154984. Its totient is φ = 10718326.

The previous prime is 21436651. The next prime is 21436691. The reversal of 21436654 is 45663412.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21436651) by changing a digit.

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, 5359162 + ... + 5359165.

It is an arithmetic number, because the mean of its divisors is an integer number (8038746).

Almost surely, 2^21436654 is an apocalyptic number.

21436654 is a deficient number, since it is larger than the sum of its proper divisors (10718330).

21436654 is a wasteful number, since it uses less digits than its factorization.

21436654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10718329.

The product of its digits is 17280, while the sum is 31.

The square root of 21436654 is about 4629.9734340491. The cubic root of 21436654 is about 277.7915297844.

The spelling of 21436654 in words is "twenty-one million, four hundred thirty-six thousand, six hundred fifty-four".