81465140 has 12 divisors (see below), whose sum is σ = 171076836. Its totient is φ = 32586048.

The previous prime is 81465119. The next prime is 81465221. The reversal of 81465140 is 4156418.

It can be written as a sum of positive squares in 2 ways, for example, as 50751376 + 30713764 = 7124^2 + 5542^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2036609 + ... + 2036648.

It is an arithmetic number, because the mean of its divisors is an integer number (14256403).

Almost surely, 2^81465140 is an apocalyptic number.

It is an amenable number.

81465140 is an abundant number, since it is smaller than the sum of its proper divisors (89611696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81465140 is a wasteful number, since it uses less digits than its factorization.

81465140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4073266 (or 4073264 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 81465140 is about 9025.8041193015. The cubic root of 81465140 is about 433.5014981765.

The spelling of 81465140 in words is "eighty-one million, four hundred sixty-five thousand, one hundred forty".