21289274 has 4 divisors (see below), whose sum is σ = 31933914. Its totient is φ = 10644636.

The previous prime is 21289273. The next prime is 21289297. The reversal of 21289274 is 47298212.

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., 18550249 + 2739025 = 4307^2 + 1655^2 .

It is not an unprimeable number, because it can be changed into a prime (21289271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5322317 + ... + 5322320.

Almost surely, 2^21289274 is an apocalyptic number.

21289274 is a deficient number, since it is larger than the sum of its proper divisors (10644640).

21289274 is a wasteful number, since it uses less digits than its factorization.

21289274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10644639.

The product of its digits is 16128, while the sum is 35.

The square root of 21289274 is about 4614.0301256060. The cubic root of 21289274 is about 277.1534466749.

The spelling of 21289274 in words is "twenty-one million, two hundred eighty-nine thousand, two hundred seventy-four".