8156381 has 4 divisors (see below), whose sum is σ = 8215200. Its totient is φ = 8097564.

The previous prime is 8156359. The next prime is 8156383. The reversal of 8156381 is 1836518.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1836518 = 2 ⋅918259.

It is a cyclic number.

It is not a de Polignac number, because 8156381 - 2¹⁴ = 8139997 is a prime.

It is a super-2 number, since 2×8156381² = 133053102034322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8156383) 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, 29201 + ... + 29478.

It is an arithmetic number, because the mean of its divisors is an integer number (2053800).

Almost surely, 2^8156381 is an apocalyptic number.

It is an amenable number.

8156381 is a deficient number, since it is larger than the sum of its proper divisors (58819).

8156381 is a wasteful number, since it uses less digits than its factorization.

8156381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58818.

The product of its digits is 5760, while the sum is 32.

The square root of 8156381 is about 2855.9378494638. The cubic root of 8156381 is about 201.2947747039.

The spelling of 8156381 in words is "eight million, one hundred fifty-six thousand, three hundred eighty-one".