378505531 has 2 divisors, whose sum is σ = 378505532. Its totient is φ = 378505530.

The previous prime is 378505529. The next prime is 378505553. The reversal of 378505531 is 135505873.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 378505531 - 2¹ = 378505529 is a prime.

It is a super-2 number, since 2×378505531² = 286532873995183922, which contains 22 as substring.

Together with 378505529, it forms a pair of twin primes.

It is equal to p_20249776 and since 378505531 and 20249776 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (378505031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 189252765 + 189252766.

It is an arithmetic number, because the mean of its divisors is an integer number (189252766).

Almost surely, 2^378505531 is an apocalyptic number.

378505531 is a deficient number, since it is larger than the sum of its proper divisors (1).

378505531 is an equidigital number, since it uses as much as digits as its factorization.

378505531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63000, while the sum is 37.

The square root of 378505531 is about 19455.2186058137. The cubic root of 378505531 is about 723.3648641402.

The spelling of 378505531 in words is "three hundred seventy-eight million, five hundred five thousand, five hundred thirty-one".