38251991 has 2 divisors, whose sum is σ = 38251992. Its totient is φ = 38251990.

The previous prime is 38251987. The next prime is 38251999. The reversal of 38251991 is 19915283.

It is a weak prime.

It is an emirp because it is prime and its reverse (19915283) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 38251991 - 2² = 38251987 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38251999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19125995 + 19125996.

It is an arithmetic number, because the mean of its divisors is an integer number (19125996).

Almost surely, 2^38251991 is an apocalyptic number.

38251991 is a deficient number, since it is larger than the sum of its proper divisors (1).

38251991 is an equidigital number, since it uses as much as digits as its factorization.

38251991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 38.

The square root of 38251991 is about 6184.8193991417. The cubic root of 38251991 is about 336.9390509869.

The spelling of 38251991 in words is "thirty-eight million, two hundred fifty-one thousand, nine hundred ninety-one".