21061628 has 12 divisors (see below), whose sum is σ = 42123312. Its totient is φ = 9026400.

The previous prime is 21061619. The next prime is 21061639. The reversal of 21061628 is 82616012.

21061628 is an admirable number.

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21061597 and 21061606.

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, 376073 + ... + 376128.

It is an arithmetic number, because the mean of its divisors is an integer number (3510276).

Almost surely, 2^21061628 is an apocalyptic number.

21061628 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21061628 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21061628 is a wasteful number, since it uses less digits than its factorization.

21061628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752212 (or 752210 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 21061628 is about 4589.2949349546. The cubic root of 21061628 is about 276.1620381550.

The spelling of 21061628 in words is "twenty-one million, sixty-one thousand, six hundred twenty-eight".