20278764 has 72 divisors (see below), whose sum is σ = 57330000. Its totient is φ = 5990400.

The previous prime is 20278763. The next prime is 20278771. The reversal of 20278764 is 46787202.

It is a super-2 number, since 2×20278764² = 822456538735392, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (20278763) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15612 + ... + 16860.

It is an arithmetic number, because the mean of its divisors is an integer number (796250).

Almost surely, 2^20278764 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20278764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28665000).

20278764 is an abundant number, since it is smaller than the sum of its proper divisors (37051236).

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

20278764 is a wasteful number, since it uses less digits than its factorization.

20278764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1311 (or 1306 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 20278764 is about 4503.1948658702. The cubic root of 20278764 is about 272.6970838099.

It can be divided in two parts, 20 and 278764, that added together give a square (278784 = 528²).

The spelling of 20278764 in words is "twenty million, two hundred seventy-eight thousand, seven hundred sixty-four".