21521494 has 16 divisors (see below), whose sum is σ = 33291648. Its totient is φ = 10426752.

The previous prime is 21521483. The next prime is 21521503. The reversal of 21521494 is 49412512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24507 + ... + 25369.

It is an arithmetic number, because the mean of its divisors is an integer number (2080728).

Almost surely, 2^21521494 is an apocalyptic number.

21521494 is a deficient number, since it is larger than the sum of its proper divisors (11770154).

21521494 is a wasteful number, since it uses less digits than its factorization.

21521494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1239.

The product of its digits is 2880, while the sum is 28.

The square root of 21521494 is about 4639.1264263868. The cubic root of 21521494 is about 278.1575198940.

The spelling of 21521494 in words is "twenty-one million, five hundred twenty-one thousand, four hundred ninety-four".