21271994 has 4 divisors (see below), whose sum is σ = 31907994. Its totient is φ = 10635996.

The previous prime is 21271973. The next prime is 21272011. The reversal of 21271994 is 49917212.

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., 13359025 + 7912969 = 3655^2 + 2813^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5317997 + ... + 5318000.

Almost surely, 2^21271994 is an apocalyptic number.

21271994 is a deficient number, since it is larger than the sum of its proper divisors (10636000).

21271994 is a wasteful number, since it uses less digits than its factorization.

21271994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10635999.

The product of its digits is 9072, while the sum is 35.

The square root of 21271994 is about 4612.1571959334. The cubic root of 21271994 is about 277.0784400792.

The spelling of 21271994 in words is "twenty-one million, two hundred seventy-one thousand, nine hundred ninety-four".