87506921 has 2 divisors, whose sum is σ = 87506922. Its totient is φ = 87506920.

The previous prime is 87506917. The next prime is 87506977. The reversal of 87506921 is 12960578.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72914521 + 14592400 = 8539^2 + 3820^2 .

It is a cyclic number.

It is not a de Polignac number, because 87506921 - 2² = 87506917 is a prime.

It is a super-2 number, since 2×87506921² = 15314922445800482, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87506981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43753460 + 43753461.

It is an arithmetic number, because the mean of its divisors is an integer number (43753461).

Almost surely, 2^87506921 is an apocalyptic number.

It is an amenable number.

87506921 is a deficient number, since it is larger than the sum of its proper divisors (1).

87506921 is an equidigital number, since it uses as much as digits as its factorization.

87506921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 87506921 is about 9354.5134026308. The cubic root of 87506921 is about 443.9637056743.

The spelling of 87506921 in words is "eighty-seven million, five hundred six thousand, nine hundred twenty-one".