27781990 has 16 divisors (see below), whose sum is σ = 52639920. Its totient is φ = 10527840.

The previous prime is 27781987. The next prime is 27781993. The reversal of 27781990 is 9918772.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (27781987) and next prime (27781993).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27781993) 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, 72921 + ... + 73300.

It is an arithmetic number, because the mean of its divisors is an integer number (3289995).

Almost surely, 2^27781990 is an apocalyptic number.

27781990 is a deficient number, since it is larger than the sum of its proper divisors (24857930).

27781990 is a wasteful number, since it uses less digits than its factorization.

27781990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146247.

The product of its (nonzero) digits is 63504, while the sum is 43.

The square root of 27781990 is about 5270.8623582864. The cubic root of 27781990 is about 302.8687395965.

The spelling of 27781990 in words is "twenty-seven million, seven hundred eighty-one thousand, nine hundred ninety".