37749221 has 2 divisors, whose sum is σ = 37749222. Its totient is φ = 37749220.

The previous prime is 37749211. The next prime is 37749223. The reversal of 37749221 is 12294773.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33292900 + 4456321 = 5770^2 + 2111^2 .

It is an emirp because it is prime and its reverse (12294773) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-37749221 is a prime.

It is a super-2 number, since 2×37749221² = 2850007372213682, which contains 22 as substring.

Together with 37749223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (37749223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18874610 + 18874611.

It is an arithmetic number, because the mean of its divisors is an integer number (18874611).

Almost surely, 2^37749221 is an apocalyptic number.

It is an amenable number.

37749221 is a deficient number, since it is larger than the sum of its proper divisors (1).

37749221 is an equidigital number, since it uses as much as digits as its factorization.

37749221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 35.

The square root of 37749221 is about 6144.0394692743. The cubic root of 37749221 is about 335.4563351067.

The spelling of 37749221 in words is "thirty-seven million, seven hundred forty-nine thousand, two hundred twenty-one".