20621766 has 16 divisors (see below), whose sum is σ = 44993088. Its totient is φ = 6249000.

The previous prime is 20621759. The next prime is 20621771. The reversal of 20621766 is 66712602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156160 + ... + 156291.

It is an arithmetic number, because the mean of its divisors is an integer number (2812068).

Almost surely, 2^20621766 is an apocalyptic number.

20621766 is an abundant number, since it is smaller than the sum of its proper divisors (24371322).

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

20621766 is a wasteful number, since it uses less digits than its factorization.

20621766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312467.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 20621766 is about 4541.1194655063. The cubic root of 20621766 is about 274.2259932446.

It can be divided in two parts, 2062 and 1766, that added together give a triangular number (3828 = T₈₇).

The spelling of 20621766 in words is "twenty million, six hundred twenty-one thousand, seven hundred sixty-six".