1018815381 has 32 divisors (see below), whose sum is σ = 1556928000. Its totient is φ = 658094400.

The previous prime is 1018815377. The next prime is 1018815401. The reversal of 1018815381 is 1835188101.

It is a happy number.

It is not a de Polignac number, because 1018815381 - 2² = 1018815377 is a prime.

It is a super-2 number, since 2×1018815381² = 2075969561124350322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1018815311) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 124195 + ... + 132143.

It is an arithmetic number, because the mean of its divisors is an integer number (48654000).

Almost surely, 2^1018815381 is an apocalyptic number.

It is an amenable number.

1018815381 is a deficient number, since it is larger than the sum of its proper divisors (538112619).

1018815381 is a wasteful number, since it uses less digits than its factorization.

1018815381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8106 (or 8100 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 36.

The square root of 1018815381 is about 31918.8875276066. The cubic root of 1018815381 is about 1006.2328643559.

The spelling of 1018815381 in words is "one billion, eighteen million, eight hundred fifteen thousand, three hundred eighty-one".