88215781 has 2 divisors, whose sum is σ = 88215782. Its totient is φ = 88215780.

The previous prime is 88215773. The next prime is 88215791. The reversal of 88215781 is 18751288.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88172100 + 43681 = 9390^2 + 209^2 .

It is a cyclic number.

It is not a de Polignac number, because 88215781 - 2³ = 88215773 is a prime.

It is a super-2 number, since 2×88215781² = 15564048034879922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (88215731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 44107890 + 44107891.

It is an arithmetic number, because the mean of its divisors is an integer number (44107891).

Almost surely, 2^88215781 is an apocalyptic number.

It is an amenable number.

88215781 is a deficient number, since it is larger than the sum of its proper divisors (1).

88215781 is an equidigital number, since it uses as much as digits as its factorization.

88215781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35840, while the sum is 40.

The square root of 88215781 is about 9392.3256438435. The cubic root of 88215781 is about 445.1592764018.

The spelling of 88215781 in words is "eighty-eight million, two hundred fifteen thousand, seven hundred eighty-one".