21361394 has 4 divisors (see below), whose sum is σ = 32042094. Its totient is φ = 10680696.

The previous prime is 21361391. The next prime is 21361397. The reversal of 21361394 is 49316312.

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

It is an interprime number because it is at equal distance from previous prime (21361391) and next prime (21361397).

It can be written as a sum of positive squares in only one way, i.e., 19035769 + 2325625 = 4363^2 + 1525^2 .

It is not an unprimeable number, because it can be changed into a prime (21361391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5340347 + ... + 5340350.

Almost surely, 2^21361394 is an apocalyptic number.

21361394 is a deficient number, since it is larger than the sum of its proper divisors (10680700).

21361394 is a wasteful number, since it uses less digits than its factorization.

21361394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10680699.

The product of its digits is 3888, while the sum is 29.

The square root of 21361394 is about 4621.8388115554. The cubic root of 21361394 is about 277.4660575859.

The spelling of 21361394 in words is "twenty-one million, three hundred sixty-one thousand, three hundred ninety-four".