21889040 has 20 divisors (see below), whose sum is σ = 50892204. Its totient is φ = 8755584.

The previous prime is 21889019. The next prime is 21889061. The reversal of 21889040 is 4098812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21889019) and next prime (21889061).

It can be written as a sum of positive squares in 2 ways, for example, as 11751184 + 10137856 = 3428^2 + 3184^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 21888988 and 21889006.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136727 + ... + 136886.

Almost surely, 2^21889040 is an apocalyptic number.

21889040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21889040 is an abundant number, since it is smaller than the sum of its proper divisors (29003164).

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

21889040 is a wasteful number, since it uses less digits than its factorization.

21889040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273626 (or 273620 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 21889040 is about 4678.5724318429. The cubic root of 21889040 is about 279.7320566010.

The spelling of 21889040 in words is "twenty-one million, eight hundred eighty-nine thousand, forty".