21426554 has 4 divisors (see below), whose sum is σ = 32139834. Its totient is φ = 10713276.

The previous prime is 21426553. The next prime is 21426583. The reversal of 21426554 is 45562412.

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., 16687225 + 4739329 = 4085^2 + 2177^2 .

It is not an unprimeable number, because it can be changed into a prime (21426553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5356637 + ... + 5356640.

Almost surely, 2^21426554 is an apocalyptic number.

21426554 is a deficient number, since it is larger than the sum of its proper divisors (10713280).

21426554 is a wasteful number, since it uses less digits than its factorization.

21426554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10713279.

The product of its digits is 9600, while the sum is 29.

The square root of 21426554 is about 4628.8825865429. The cubic root of 21426554 is about 277.7478952506.

Adding to 21426554 its reverse (45562412), we get a palindrome (66988966).

The spelling of 21426554 in words is "twenty-one million, four hundred twenty-six thousand, five hundred fifty-four".