21029838 has 32 divisors (see below), whose sum is σ = 44221056. Its totient is φ = 6658848.

The previous prime is 21029837. The next prime is 21029839. The reversal of 21029838 is 83892012.

It is an interprime number because it is at equal distance from previous prime (21029837) and next prime (21029839).

It is a junction number, because it is equal to n+sod(n) for n = 21029799 and 21029808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21029831) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8445 + ... + 10647.

It is an arithmetic number, because the mean of its divisors is an integer number (1381908).

Almost surely, 2^21029838 is an apocalyptic number.

21029838 is an abundant number, since it is smaller than the sum of its proper divisors (23191218).

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

21029838 is a wasteful number, since it uses less digits than its factorization.

21029838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2288.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 21029838 is about 4585.8301320481. The cubic root of 21029838 is about 276.0230237042.

The spelling of 21029838 in words is "twenty-one million, twenty-nine thousand, eight hundred thirty-eight".