87657721237501 has 2 divisors, whose sum is σ = 87657721237502. Its totient is φ = 87657721237500.

The previous prime is 87657721237487. The next prime is 87657721237529. The reversal of 87657721237501 is 10573212775678.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55236927944025 + 32420793293476 = 7432155^2 + 5693926^2 .

It is a cyclic number.

It is not a de Polignac number, because 87657721237501 - 2²⁹ = 87657184366589 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 87657721237501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87657721237561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43828860618750 + 43828860618751.

It is an arithmetic number, because the mean of its divisors is an integer number (43828860618751).

Almost surely, 2^{87657721237501} is an apocalyptic number.

It is an amenable number.

87657721237501 is a deficient number, since it is larger than the sum of its proper divisors (1).

87657721237501 is an equidigital number, since it uses as much as digits as its factorization.

87657721237501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34574400, while the sum is 61.

The spelling of 87657721237501 in words is "eighty-seven trillion, six hundred fifty-seven billion, seven hundred twenty-one million, two hundred thirty-seven thousand, five hundred one".