20499666 has 32 divisors (see below), whose sum is σ = 45086976. Its totient is φ = 6162000.

The previous prime is 20499659. The next prime is 20499673. The reversal of 20499666 is 66699402.

It is an interprime number because it is at equal distance from previous prime (20499659) and next prime (20499673).

It is a super-2 number, since 2×20499666² = 840472612223112, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7461 + ... + 9831.

It is an arithmetic number, because the mean of its divisors is an integer number (1408968).

Almost surely, 2^20499666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20499666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22543488).

20499666 is an abundant number, since it is smaller than the sum of its proper divisors (24587310).

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

20499666 is a wasteful number, since it uses less digits than its factorization.

20499666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2518.

The product of its (nonzero) digits is 139968, while the sum is 42.

The square root of 20499666 is about 4527.6556847888. The cubic root of 20499666 is about 273.6836973765.

The spelling of 20499666 in words is "twenty million, four hundred ninety-nine thousand, six hundred sixty-six".