20621776 has 40 divisors (see below), whose sum is σ = 46139904. Its totient is φ = 8745600.

The previous prime is 20621771. The next prime is 20621791. The reversal of 20621776 is 67712602.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20621771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10401 + ... + 12223.

Almost surely, 2^20621776 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 20621776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23069952).

20621776 is an abundant number, since it is smaller than the sum of its proper divisors (25518128).

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

20621776 is a wasteful number, since it uses less digits than its factorization.

20621776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1939 (or 1933 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 20621776 is about 4541.1205665562. The cubic root of 20621776 is about 274.2260375709.

The spelling of 20621776 in words is "twenty million, six hundred twenty-one thousand, seven hundred seventy-six".