27780640 has 24 divisors (see below), whose sum is σ = 65632140. Its totient is φ = 11112192.

The previous prime is 27780631. The next prime is 27780653. The reversal of 27780640 is 4608772.

It can be written as a sum of positive squares in 2 ways, for example, as 27583504 + 197136 = 5252^2 + 444^2 .

It is a junction number, because it is equal to n+sod(n) for n = 27780596 and 27780605.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86655 + ... + 86974.

Almost surely, 2^27780640 is an apocalyptic number.

27780640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

27780640 is an abundant number, since it is smaller than the sum of its proper divisors (37851500).

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

27780640 is a wasteful number, since it uses less digits than its factorization.

27780640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173644 (or 173636 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 34.

The square root of 27780640 is about 5270.7342941947. The cubic root of 27780640 is about 302.8638337873.

The spelling of 27780640 in words is "twenty-seven million, seven hundred eighty thousand, six hundred forty".