451621987 has 2 divisors, whose sum is σ = 451621988. Its totient is φ = 451621986.

The previous prime is 451621921. The next prime is 451621999. The reversal of 451621987 is 789126154.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 451621987 - 2¹⁵ = 451589219 is a prime.

It is not a weakly prime, because it can be changed into another prime (451621087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 225810993 + 225810994.

It is an arithmetic number, because the mean of its divisors is an integer number (225810994).

Almost surely, 2^451621987 is an apocalyptic number.

451621987 is a deficient number, since it is larger than the sum of its proper divisors (1).

451621987 is an equidigital number, since it uses as much as digits as its factorization.

451621987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 43.

The square root of 451621987 is about 21251.3996480232. The cubic root of 451621987 is about 767.2290276220.

The spelling of 451621987 in words is "four hundred fifty-one million, six hundred twenty-one thousand, nine hundred eighty-seven".