20280630 has 32 divisors (see below), whose sum is σ = 49065984. Its totient is φ = 5364576.

The previous prime is 20280607. The next prime is 20280661. The reversal of 20280630 is 3608202.

It is a super-2 number, since 2×20280630² = 822607906393800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20280597 and 20280606.

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, 1149 + ... + 6471.

It is an arithmetic number, because the mean of its divisors is an integer number (1533312).

Almost surely, 2^20280630 is an apocalyptic number.

20280630 is an abundant number, since it is smaller than the sum of its proper divisors (28785354).

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

20280630 is a wasteful number, since it uses less digits than its factorization.

20280630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5460.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 20280630 is about 4503.4020473415. The cubic root of 20280630 is about 272.7054478495.

Adding to 20280630 its reverse (3608202), we get a palindrome (23888832).

It can be divided in two parts, 20280 and 630, that added together give a triangular number (20910 = T₂₀₄).

The spelling of 20280630 in words is "twenty million, two hundred eighty thousand, six hundred thirty".