81407548 has 24 divisors (see below), whose sum is σ = 146723472. Its totient is φ = 39492864.

The previous prime is 81407539. The next prime is 81407549. The reversal of 81407548 is 84570418.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81407549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82836 + ... + 83812.

It is an arithmetic number, because the mean of its divisors is an integer number (6113478).

Almost surely, 2^81407548 is an apocalyptic number.

It is an amenable number.

81407548 is a deficient number, since it is larger than the sum of its proper divisors (65315924).

81407548 is a wasteful number, since it uses less digits than its factorization.

81407548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1581 (or 1579 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 37.

The square root of 81407548 is about 9022.6131469769. The cubic root of 81407548 is about 433.3993190771.

The spelling of 81407548 in words is "eighty-one million, four hundred seven thousand, five hundred forty-eight".