20477664 has 96 divisors (see below), whose sum is σ = 60510240. Its totient is φ = 6736896.

The previous prime is 20477647. The next prime is 20477693. The reversal of 20477664 is 46677402.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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, 118282 + ... + 118454.

It is an arithmetic number, because the mean of its divisors is an integer number (630315).

Almost surely, 2^20477664 is an apocalyptic number.

20477664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20477664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30255120).

20477664 is an abundant number, since it is smaller than the sum of its proper divisors (40032576).

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

20477664 is a wasteful number, since it uses less digits than its factorization.

20477664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329 (or 315 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 36.

The square root of 20477664 is about 4525.2252982586. The cubic root of 20477664 is about 273.5857487191.

The spelling of 20477664 in words is "twenty million, four hundred seventy-seven thousand, six hundred sixty-four".