21611494 has 8 divisors (see below), whose sum is σ = 32499288. Its totient is φ = 10778400.

The previous prime is 21611461. The next prime is 21611519. The reversal of 21611494 is 49411612.

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

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 12672 + ... + 14275.

It is an arithmetic number, because the mean of its divisors is an integer number (4062411).

Almost surely, 2^21611494 is an apocalyptic number.

21611494 is a deficient number, since it is larger than the sum of its proper divisors (10887794).

21611494 is a wasteful number, since it uses less digits than its factorization.

21611494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27350.

The product of its digits is 1728, while the sum is 28.

The square root of 21611494 is about 4648.8164085066. The cubic root of 21611494 is about 278.5447197962.

It can be divided in two parts, 2161 and 1494, that added together give a triangular number (3655 = T₈₅).

The spelling of 21611494 in words is "twenty-one million, six hundred eleven thousand, four hundred ninety-four".