21166626 has 16 divisors (see below), whose sum is σ = 45589824. Its totient is φ = 6512784.

The previous prime is 21166609. The next prime is 21166643. The reversal of 21166626 is 62666112.

It is an interprime number because it is at equal distance from previous prime (21166609) and next prime (21166643).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21166593 and 21166602.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135606 + ... + 135761.

It is an arithmetic number, because the mean of its divisors is an integer number (2849364).

Almost surely, 2^21166626 is an apocalyptic number.

21166626 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21166626 is an abundant number, since it is smaller than the sum of its proper divisors (24423198).

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

21166626 is a wasteful number, since it uses less digits than its factorization.

21166626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271385.

The product of its digits is 5184, while the sum is 30.

The square root of 21166626 is about 4600.7201610183. The cubic root of 21166626 is about 276.6201921904.

It can be divided in two parts, 2 and 1166626, that added together give a triangular number (1166628 = T₁₅₂₇).

The spelling of 21166626 in words is "twenty-one million, one hundred sixty-six thousand, six hundred twenty-six".