1287079621 has 2 divisors, whose sum is σ = 1287079622. Its totient is φ = 1287079620.

The previous prime is 1287079501. The next prime is 1287079637. The reversal of 1287079621 is 1269707821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 881258596 + 405821025 = 29686^2 + 20145^2 .

It is a cyclic number.

It is not a de Polignac number, because 1287079621 - 2¹⁵ = 1287046853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1287079681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643539810 + 643539811.

It is an arithmetic number, because the mean of its divisors is an integer number (643539811).

Almost surely, 2^1287079621 is an apocalyptic number.

It is an amenable number.

1287079621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287079621 is an equidigital number, since it uses as much as digits as its factorization.

1287079621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 43.

The square root of 1287079621 is about 35875.8919192262. The cubic root of 1287079621 is about 1087.7651431892.

The spelling of 1287079621 in words is "one billion, two hundred eighty-seven million, seventy-nine thousand, six hundred twenty-one".