21424988 has 12 divisors (see below), whose sum is σ = 40377960. Its totient is φ = 9888432.

The previous prime is 21424973. The next prime is 21425003. The reversal of 21424988 is 88942412.

It is an interprime number because it is at equal distance from previous prime (21424973) and next prime (21425003).

It is a super-2 number, since 2×21424988² = 918060221600288, which contains 22 as substring.

It is a congruent number.

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, 205958 + ... + 206061.

It is an arithmetic number, because the mean of its divisors is an integer number (3364830).

Almost surely, 2^21424988 is an apocalyptic number.

It is an amenable number.

21424988 is a deficient number, since it is larger than the sum of its proper divisors (18952972).

21424988 is a wasteful number, since it uses less digits than its factorization.

21424988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412036 (or 412034 counting only the distinct ones).

The product of its digits is 36864, while the sum is 38.

The square root of 21424988 is about 4628.7134281569. The cubic root of 21424988 is about 277.7411285100.

The spelling of 21424988 in words is "twenty-one million, four hundred twenty-four thousand, nine hundred eighty-eight".