987611221 has 2 divisors, whose sum is σ = 987611222. Its totient is φ = 987611220.

The previous prime is 987611179. The next prime is 987611249. The reversal of 987611221 is 122116789.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 504227025 + 483384196 = 22455^2 + 21986^2 .

It is an emirp because it is prime and its reverse (122116789) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 987611221 - 2¹¹ = 987609173 is a prime.

It is a super-2 number, since 2×987611221² = 1950751847690221682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (987611921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493805610 + 493805611.

It is an arithmetic number, because the mean of its divisors is an integer number (493805611).

Almost surely, 2^987611221 is an apocalyptic number.

It is an amenable number.

987611221 is a deficient number, since it is larger than the sum of its proper divisors (1).

987611221 is an equidigital number, since it uses as much as digits as its factorization.

987611221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 37.

The square root of 987611221 is about 31426.2823286497. The cubic root of 987611221 is about 995.8532351097.

The spelling of 987611221 in words is "nine hundred eighty-seven million, six hundred eleven thousand, two hundred twenty-one".