21458366 has 4 divisors (see below), whose sum is σ = 32187552. Its totient is φ = 10729182.

The previous prime is 21458363. The next prime is 21458377. The reversal of 21458366 is 66385412.

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

It is a super-2 number, since 2×21458366² = 920922942779912, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21458363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5364590 + ... + 5364593.

It is an arithmetic number, because the mean of its divisors is an integer number (8046888).

Almost surely, 2^21458366 is an apocalyptic number.

21458366 is a deficient number, since it is larger than the sum of its proper divisors (10729186).

21458366 is a wasteful number, since it uses less digits than its factorization.

21458366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10729185.

The product of its digits is 34560, while the sum is 35.

The square root of 21458366 is about 4632.3175625166. The cubic root of 21458366 is about 277.8852846920.

The spelling of 21458366 in words is "twenty-one million, four hundred fifty-eight thousand, three hundred sixty-six".