20770820 has 48 divisors (see below), whose sum is σ = 50440320. Its totient is φ = 7037184.

The previous prime is 20770807. The next prime is 20770823. The reversal of 20770820 is 2807702.

It is a self number, because there is not a number n which added to its sum of digits gives 20770820.

It is not an unprimeable number, because it can be changed into a prime (20770823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11627 + ... + 13293.

It is an arithmetic number, because the mean of its divisors is an integer number (1050840).

Almost surely, 2^20770820 is an apocalyptic number.

20770820 is a gapful number since it is divisible by the number (20) 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 20770820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25220160).

20770820 is an abundant number, since it is smaller than the sum of its proper divisors (29669500).

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

20770820 is a wasteful number, since it uses less digits than its factorization.

20770820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1772 (or 1770 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 26.

The square root of 20770820 is about 4557.5015085022. The cubic root of 20770820 is about 274.8851090317.

The spelling of 20770820 in words is "twenty million, seven hundred seventy thousand, eight hundred twenty".