37666381 has 2 divisors, whose sum is σ = 37666382. Its totient is φ = 37666380.

The previous prime is 37666319. The next prime is 37666393. The reversal of 37666381 is 18366673.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24950025 + 12716356 = 4995^2 + 3566^2 .

It is a cyclic number.

It is not a de Polignac number, because 37666381 - 2²¹ = 35569229 is a prime.

It is a super-2 number, since 2×37666381² = 2837512515274322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (37666301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18833190 + 18833191.

It is an arithmetic number, because the mean of its divisors is an integer number (18833191).

Almost surely, 2^37666381 is an apocalyptic number.

It is an amenable number.

37666381 is a deficient number, since it is larger than the sum of its proper divisors (1).

37666381 is an equidigital number, since it uses as much as digits as its factorization.

37666381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 40.

The square root of 37666381 is about 6137.2942735378. The cubic root of 37666381 is about 335.2107710524.

The spelling of 37666381 in words is "thirty-seven million, six hundred sixty-six thousand, three hundred eighty-one".