21131354 has 4 divisors (see below), whose sum is σ = 31697034. Its totient is φ = 10565676.

The previous prime is 21131333. The next prime is 21131389. The reversal of 21131354 is 45313112.

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., 15015625 + 6115729 = 3875^2 + 2473^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5282837 + ... + 5282840.

Almost surely, 2^21131354 is an apocalyptic number.

21131354 is a deficient number, since it is larger than the sum of its proper divisors (10565680).

21131354 is a wasteful number, since it uses less digits than its factorization.

21131354 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10565679.

The product of its digits is 360, while the sum is 20.

The square root of 21131354 is about 4596.8852498186. The cubic root of 21131354 is about 276.4664537519.

Adding to 21131354 its reverse (45313112), we get a palindrome (66444466).

The spelling of 21131354 in words is "twenty-one million, one hundred thirty-one thousand, three hundred fifty-four".