21945754 has 4 divisors (see below), whose sum is σ = 32918634. Its totient is φ = 10972876.

The previous prime is 21945751. The next prime is 21945769. The reversal of 21945754 is 45754912.

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., 20493729 + 1452025 = 4527^2 + 1205^2 .

It is a super-2 number, since 2×21945754² = 963232237257032, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21945751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5486437 + ... + 5486440.

Almost surely, 2^21945754 is an apocalyptic number.

21945754 is a deficient number, since it is larger than the sum of its proper divisors (10972880).

21945754 is a wasteful number, since it uses less digits than its factorization.

21945754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10972879.

The product of its digits is 50400, while the sum is 37.

The square root of 21945754 is about 4684.6295477871. The cubic root of 21945754 is about 279.9734413585.

The spelling of 21945754 in words is "twenty-one million, nine hundred forty-five thousand, seven hundred fifty-four".