88190821 has 2 divisors, whose sum is σ = 88190822. Its totient is φ = 88190820.

The previous prime is 88190819. The next prime is 88190857. The reversal of 88190821 is 12809188.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87628321 + 562500 = 9361^2 + 750^2 .

It is a cyclic number.

It is not a de Polignac number, because 88190821 - 2¹ = 88190819 is a prime.

Together with 88190819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (88190801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 44095410 + 44095411.

It is an arithmetic number, because the mean of its divisors is an integer number (44095411).

Almost surely, 2^88190821 is an apocalyptic number.

It is an amenable number.

88190821 is a deficient number, since it is larger than the sum of its proper divisors (1).

88190821 is an equidigital number, since it uses as much as digits as its factorization.

88190821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 88190821 is about 9390.9968054515. The cubic root of 88190821 is about 445.1172876045.

The spelling of 88190821 in words is "eighty-eight million, one hundred ninety thousand, eight hundred twenty-one".