21840654 has 32 divisors (see below), whose sum is σ = 49299840. Its totient is φ = 6389600.

The previous prime is 21840641. The next prime is 21840667. The reversal of 21840654 is 45604812.

It is an interprime number because it is at equal distance from previous prime (21840641) and next prime (21840667).

It is a super-3 number, since 3×21840654³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

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 in 15 ways as a sum of consecutive naturals, for example, 3792 + ... + 7619.

It is an arithmetic number, because the mean of its divisors is an integer number (1540620).

Almost surely, 2^21840654 is an apocalyptic number.

21840654 is an abundant number, since it is smaller than the sum of its proper divisors (27459186).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21840654 is a wasteful number, since it uses less digits than its factorization.

21840654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11456.

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 21840654 is about 4673.3985492359. The cubic root of 21840654 is about 279.5257874554.

The spelling of 21840654 in words is "twenty-one million, eight hundred forty thousand, six hundred fifty-four".