37666991 has 8 divisors (see below), whose sum is σ = 38405664. Its totient is φ = 36934240.

The previous prime is 37666973. The next prime is 37667009. The reversal of 37666991 is 19966673.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (37666973) and next prime (37667009).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 37666991 - 2¹⁴ = 37650607 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 (37666921) 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, 12641 + ... + 15333.

It is an arithmetic number, because the mean of its divisors is an integer number (4800708).

Almost surely, 2^37666991 is an apocalyptic number.

37666991 is a deficient number, since it is larger than the sum of its proper divisors (738673).

37666991 is a wasteful number, since it uses less digits than its factorization.

37666991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2961.

The product of its digits is 367416, while the sum is 47.

The square root of 37666991 is about 6137.3439695034. The cubic root of 37666991 is about 335.2125806013.

The spelling of 37666991 in words is "thirty-seven million, six hundred sixty-six thousand, nine hundred ninety-one".