21629854 has 4 divisors (see below), whose sum is σ = 32444784. Its totient is φ = 10814926.

The previous prime is 21629849. The next prime is 21629863. The reversal of 21629854 is 45892612.

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

It is a super-2 number, since 2×21629854² = 935701168122632, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5407462 + ... + 5407465.

It is an arithmetic number, because the mean of its divisors is an integer number (8111196).

Almost surely, 2^21629854 is an apocalyptic number.

21629854 is a deficient number, since it is larger than the sum of its proper divisors (10814930).

21629854 is a wasteful number, since it uses less digits than its factorization.

21629854 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10814929.

The product of its digits is 34560, while the sum is 37.

The square root of 21629854 is about 4650.7906854641. The cubic root of 21629854 is about 278.6235764996.

The spelling of 21629854 in words is "twenty-one million, six hundred twenty-nine thousand, eight hundred fifty-four".