21613274 has 4 divisors (see below), whose sum is σ = 32419914. Its totient is φ = 10806636.

The previous prime is 21613259. The next prime is 21613309. The reversal of 21613274 is 47231612.

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

It can be written as a sum of positive squares in only one way, i.e., 21576025 + 37249 = 4645^2 + 193^2 .

It is a super-2 number, since 2×21613274² = 934267225998152, which contains 22 as substring.

It is a Curzon 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 as a sum of consecutive naturals, namely, 5403317 + ... + 5403320.

Almost surely, 2^21613274 is an apocalyptic number.

21613274 is a deficient number, since it is larger than the sum of its proper divisors (10806640).

21613274 is a wasteful number, since it uses less digits than its factorization.

21613274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10806639.

The product of its digits is 2016, while the sum is 26.

The square root of 21613274 is about 4649.0078511442. The cubic root of 21613274 is about 278.5523668996.

Adding to 21613274 its reverse (47231612), we get a palindrome (68844886).

The spelling of 21613274 in words is "twenty-one million, six hundred thirteen thousand, two hundred seventy-four".