78521541 has 16 divisors (see below), whose sum is σ = 120839808. Its totient is φ = 44424000.

The previous prime is 78521539. The next prime is 78521551. The reversal of 78521541 is 14512587.

It is not a de Polignac number, because 78521541 - 2¹ = 78521539 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78521551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16390 + ... + 20631.

It is an arithmetic number, because the mean of its divisors is an integer number (7552488).

Almost surely, 2^78521541 is an apocalyptic number.

It is an amenable number.

78521541 is a deficient number, since it is larger than the sum of its proper divisors (42318267).

78521541 is a wasteful number, since it uses less digits than its factorization.

78521541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37132.

The product of its digits is 11200, while the sum is 33.

The square root of 78521541 is about 8861.2381189087. The cubic root of 78521541 is about 428.2160469938.

The spelling of 78521541 in words is "seventy-eight million, five hundred twenty-one thousand, five hundred forty-one".