81019378 has 16 divisors (see below), whose sum is σ = 134447040. Its totient is φ = 36307600.

The previous prime is 81019369. The next prime is 81019387. The reversal of 81019378 is 87391018.

It is an interprime number because it is at equal distance from previous prime (81019369) and next prime (81019387).

It is a super-2 number, since 2×81019378² = 13128279223013768, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24373 + ... + 27496.

It is an arithmetic number, because the mean of its divisors is an integer number (8402940).

Almost surely, 2^81019378 is an apocalyptic number.

81019378 is a deficient number, since it is larger than the sum of its proper divisors (53427662).

81019378 is a wasteful number, since it uses less digits than its factorization.

81019378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51953.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 81019378 is about 9001.0764911759. The cubic root of 81019378 is about 432.7093719364.

The spelling of 81019378 in words is "eighty-one million, nineteen thousand, three hundred seventy-eight".