20680780 has 24 divisors (see below), whose sum is σ = 44605008. Its totient is φ = 8048448.

The previous prime is 20680747. The next prime is 20680787. The reversal of 20680780 is 8708602.

20680780 = T₅₅ + T₅₆ + ... + T₄₉₈.

It is a super-2 number, since 2×20680780² = 855389322816800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20680787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13234 + ... + 14713.

It is an arithmetic number, because the mean of its divisors is an integer number (1858542).

Almost surely, 2^20680780 is an apocalyptic number.

20680780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20680780 is an abundant number, since it is smaller than the sum of its proper divisors (23924228).

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

20680780 is a wasteful number, since it uses less digits than its factorization.

20680780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27993 (or 27991 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 20680780 is about 4547.6125604541. The cubic root of 20680780 is about 274.4873313530.

The spelling of 20680780 in words is "twenty million, six hundred eighty thousand, seven hundred eighty".