27661590637 has 4 divisors (see below), whose sum is σ = 28615438620. Its totient is φ = 26707742656.

The previous prime is 27661590631. The next prime is 27661590653. The reversal of 27661590637 is 73609516672.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21917618116 + 5743972521 = 148046^2 + 75789^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27661590637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27661590631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 476923948 + ... + 476924005.

It is an arithmetic number, because the mean of its divisors is an integer number (7153859655).

Almost surely, 2^27661590637 is an apocalyptic number.

It is an amenable number.

27661590637 is a deficient number, since it is larger than the sum of its proper divisors (953847983).

27661590637 is an equidigital number, since it uses as much as digits as its factorization.

27661590637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953847982.

The product of its (nonzero) digits is 2857680, while the sum is 52.

The spelling of 27661590637 in words is "twenty-seven billion, six hundred sixty-one million, five hundred ninety thousand, six hundred thirty-seven".