38991967 has 4 divisors (see below), whose sum is σ = 44562256. Its totient is φ = 33421680.

The previous prime is 38991961. The next prime is 38991973. The reversal of 38991967 is 76919983.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76919983 = 7 ⋅10988569.

It is an interprime number because it is at equal distance from previous prime (38991961) and next prime (38991973).

It is a cyclic number.

It is not a de Polignac number, because 38991967 - 2⁷ = 38991839 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 (38991961) 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, 2785134 + ... + 2785147.

It is an arithmetic number, because the mean of its divisors is an integer number (11140564).

Almost surely, 2^38991967 is an apocalyptic number.

38991967 is a deficient number, since it is larger than the sum of its proper divisors (5570289).

38991967 is an equidigital number, since it uses as much as digits as its factorization.

38991967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5570288.

The product of its digits is 734832, while the sum is 52.

The square root of 38991967 is about 6244.3548105469. The cubic root of 38991967 is about 339.0978592825.

The spelling of 38991967 in words is "thirty-eight million, nine hundred ninety-one thousand, nine hundred sixty-seven".