21451274 has 8 divisors (see below), whose sum is σ = 34652100. Its totient is φ = 9900576.

The previous prime is 21451237. The next prime is 21451277. The reversal of 21451274 is 47215412.

It can be written as a sum of positive squares in 2 ways, for example, as 18705625 + 2745649 = 4325^2 + 1657^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (26), and also a Moran number because the ratio is a prime number: 825049 = 21451274 / (2 + 1 + 4 + 5 + 1 + 2 + 7 + 4).

It is not an unprimeable number, because it can be changed into a prime (21451277) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 412499 + ... + 412550.

Almost surely, 2^21451274 is an apocalyptic number.

21451274 is a deficient number, since it is larger than the sum of its proper divisors (13200826).

21451274 is a wasteful number, since it uses less digits than its factorization.

21451274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825064.

The product of its digits is 2240, while the sum is 26.

The square root of 21451274 is about 4631.5520076968. The cubic root of 21451274 is about 277.8546675799.

Adding to 21451274 its reverse (47215412), we get a palindrome (68666686).

The spelling of 21451274 in words is "twenty-one million, four hundred fifty-one thousand, two hundred seventy-four".