87226781 has 4 divisors (see below), whose sum is σ = 87421500. Its totient is φ = 87032064.

The previous prime is 87226771. The next prime is 87226801. The reversal of 87226781 is 18762278.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30360100 + 56866681 = 5510^2 + 7541^2 .

It is a cyclic number.

It is not a de Polignac number, because 87226781 - 2⁶ = 87226717 is a prime.

It is a super-2 number, since 2×87226781² = 15217022647243922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87226771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96686 + ... + 97583.

It is an arithmetic number, because the mean of its divisors is an integer number (21855375).

Almost surely, 2^87226781 is an apocalyptic number.

It is an amenable number.

87226781 is a deficient number, since it is larger than the sum of its proper divisors (194719).

87226781 is a wasteful number, since it uses less digits than its factorization.

87226781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194718.

The product of its digits is 75264, while the sum is 41.

The square root of 87226781 is about 9339.5278788598. The cubic root of 87226781 is about 443.4894386223.

The spelling of 87226781 in words is "eighty-seven million, two hundred twenty-six thousand, seven hundred eighty-one".