84077381521 has 27 divisors (see below), whose sum is σ = 102298347963. Its totient is φ = 68894733600.

The previous prime is 84077381489. The next prime is 84077381527. The reversal of 84077381521 is 12518377048.

The square root of 84077381521 is 289961.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 10917951121 + 73159430400 = 104489^2 + 270480^2 .

It is not a de Polignac number, because 84077381521 - 2⁵ = 84077381489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (84077381527) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 46682821 + ... + 46684621.

Almost surely, 2^84077381521 is an apocalyptic number.

84077381521 is the 289961-st square number.

84077381521 is the 144981-st centered octagonal number.

It is an amenable number.

84077381521 is a deficient number, since it is larger than the sum of its proper divisors (18220966442).

84077381521 is an frugal number, since it uses more digits than its factorization.

84077381521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3662 (or 1831 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 46.

The spelling of 84077381521 in words is "eighty-four billion, seventy-seven million, three hundred eighty-one thousand, five hundred twenty-one".