21400754 has 4 divisors (see below), whose sum is σ = 32101134. Its totient is φ = 10700376.

The previous prime is 21400751. The next prime is 21400781. The reversal of 21400754 is 45700412.

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., 20043529 + 1357225 = 4477^2 + 1165^2 .

It is not an unprimeable number, because it can be changed into a prime (21400751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5350187 + ... + 5350190.

Almost surely, 2^21400754 is an apocalyptic number.

21400754 is a deficient number, since it is larger than the sum of its proper divisors (10700380).

21400754 is a wasteful number, since it uses less digits than its factorization.

21400754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10700379.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 21400754 is about 4626.0948974270. The cubic root of 21400754 is about 277.6363704917.

The spelling of 21400754 in words is "twenty-one million, four hundred thousand, seven hundred fifty-four".