21554408 has 8 divisors (see below), whose sum is σ = 40414530. Its totient is φ = 10777200.

The previous prime is 21554383. The next prime is 21554443. The reversal of 21554408 is 80445512.

It can be written as a sum of positive squares in only one way, i.e., 21325924 + 228484 = 4618^2 + 478^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

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, 1347143 + ... + 1347158.

Almost surely, 2^21554408 is an apocalyptic number.

It is an amenable number.

21554408 is a deficient number, since it is larger than the sum of its proper divisors (18860122).

21554408 is a wasteful number, since it uses less digits than its factorization.

21554408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2694307 (or 2694303 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 29.

The square root of 21554408 is about 4642.6725062188. The cubic root of 21554408 is about 278.2992481796.

The spelling of 21554408 in words is "twenty-one million, five hundred fifty-four thousand, four hundred eight".