21029426 has 8 divisors (see below), whose sum is σ = 34411824. Its totient is φ = 9558820.

The previous prime is 21029401. The next prime is 21029443. The reversal of 21029426 is 62492012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21029395 and 21029404.

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, 477920 + ... + 477963.

It is an arithmetic number, because the mean of its divisors is an integer number (4301478).

Almost surely, 2^21029426 is an apocalyptic number.

21029426 is a deficient number, since it is larger than the sum of its proper divisors (13382398).

21029426 is a wasteful number, since it uses less digits than its factorization.

21029426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 955896.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 21029426 is about 4585.7852108445. The cubic root of 21029426 is about 276.0212211506.

The spelling of 21029426 in words is "twenty-one million, twenty-nine thousand, four hundred twenty-six".