21623086 has 4 divisors (see below), whose sum is σ = 32434632. Its totient is φ = 10811542.

The previous prime is 21623081. The next prime is 21623101. The reversal of 21623086 is 68032612.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623081) 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, 5405770 + ... + 5405773.

It is an arithmetic number, because the mean of its divisors is an integer number (8108658).

Almost surely, 2^21623086 is an apocalyptic number.

21623086 is a deficient number, since it is larger than the sum of its proper divisors (10811546).

21623086 is a wasteful number, since it uses less digits than its factorization.

21623086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10811545.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 21623086 is about 4650.0630103258. The cubic root of 21623086 is about 278.5945129488.

Adding to 21623086 its reverse (68032612), we get a palindrome (89655698).

The spelling of 21623086 in words is "twenty-one million, six hundred twenty-three thousand, eighty-six".