378815531 has 2 divisors, whose sum is σ = 378815532. Its totient is φ = 378815530.

The previous prime is 378815527. The next prime is 378815533. The reversal of 378815531 is 135518873.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 378815531 - 2² = 378815527 is a prime.

It is a super-2 number, since 2×378815531² = 287002413053623922, which contains 22 as substring.

Together with 378815533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (378815533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 189407765 + 189407766.

It is an arithmetic number, because the mean of its divisors is an integer number (189407766).

Almost surely, 2^378815531 is an apocalyptic number.

378815531 is a deficient number, since it is larger than the sum of its proper divisors (1).

378815531 is an equidigital number, since it uses as much as digits as its factorization.

378815531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 41.

The square root of 378815531 is about 19463.1839892655. The cubic root of 378815531 is about 723.5622913887.

The spelling of 378815531 in words is "three hundred seventy-eight million, eight hundred fifteen thousand, five hundred thirty-one".