81753478 has 4 divisors (see below), whose sum is σ = 122630220. Its totient is φ = 40876738.

The previous prime is 81753473. The next prime is 81753491. The reversal of 81753478 is 87435718.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87435718 = 2 ⋅43717859.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81753473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20438368 + ... + 20438371.

It is an arithmetic number, because the mean of its divisors is an integer number (30657555).

Almost surely, 2^81753478 is an apocalyptic number.

81753478 is a deficient number, since it is larger than the sum of its proper divisors (40876742).

81753478 is a wasteful number, since it uses less digits than its factorization.

81753478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40876741.

The product of its digits is 188160, while the sum is 43.

The square root of 81753478 is about 9041.7629918064. The cubic root of 81753478 is about 434.0123415265.

The spelling of 81753478 in words is "eighty-one million, seven hundred fifty-three thousand, four hundred seventy-eight".