987001621 has 2 divisors, whose sum is σ = 987001622. Its totient is φ = 987001620.

The previous prime is 987001583. The next prime is 987001627. The reversal of 987001621 is 126100789.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 699020721 + 287980900 = 26439^2 + 16970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-987001621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (987001627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493500810 + 493500811.

It is an arithmetic number, because the mean of its divisors is an integer number (493500811).

Almost surely, 2^987001621 is an apocalyptic number.

It is an amenable number.

987001621 is a deficient number, since it is larger than the sum of its proper divisors (1).

987001621 is an equidigital number, since it uses as much as digits as its factorization.

987001621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 987001621 is about 31416.5819432987. The cubic root of 987001621 is about 995.6482971522.

The spelling of 987001621 in words is "nine hundred eighty-seven million, one thousand, six hundred twenty-one".