87316561121505 has 64 divisors (see below), whose sum is σ = 148456896277248. Its totient is φ = 43671770726400.

The previous prime is 87316561121453. The next prime is 87316561121507. The reversal of 87316561121505 is 50512116561378.

It is a de Polignac number, because none of the positive numbers 2^k-87316561121505 is a prime.

It is a super-4 number, since 4×87316561121505⁴ (a number of 57 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (87316561121507) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1508003055 + ... + 1508060955.

It is an arithmetic number, because the mean of its divisors is an integer number (2319639004332).

Almost surely, 2^{87316561121505} is an apocalyptic number.

87316561121505 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

87316561121505 is a deficient number, since it is larger than the sum of its proper divisors (61140335155743).

87316561121505 is a wasteful number, since it uses less digits than its factorization.

87316561121505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79106.

The product of its (nonzero) digits is 1512000, while the sum is 51.

The spelling of 87316561121505 in words is "eighty-seven trillion, three hundred sixteen billion, five hundred sixty-one million, one hundred twenty-one thousand, five hundred five".