1551621983 has 2 divisors, whose sum is σ = 1551621984. Its totient is φ = 1551621982.

The previous prime is 1551621971. The next prime is 1551621989. The reversal of 1551621983 is 3891261551.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1551621983 - 2⁶ = 1551621919 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1551621983.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1551621989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775810991 + 775810992.

It is an arithmetic number, because the mean of its divisors is an integer number (775810992).

Almost surely, 2^1551621983 is an apocalyptic number.

1551621983 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551621983 is an equidigital number, since it uses as much as digits as its factorization.

1551621983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64800, while the sum is 41.

The square root of 1551621983 is about 39390.6331886148. The cubic root of 1551621983 is about 1157.6980665463.

The spelling of 1551621983 in words is "one billion, five hundred fifty-one million, six hundred twenty-one thousand, nine hundred eighty-three".