1550421979 has 2 divisors, whose sum is σ = 1550421980. Its totient is φ = 1550421978.

The previous prime is 1550421967. The next prime is 1550422087. The reversal of 1550421979 is 9791240551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1550421979 - 2¹⁹ = 1549897691 is a prime.

It is not a weakly prime, because it can be changed into another prime (1550521979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775210989 + 775210990.

It is an arithmetic number, because the mean of its divisors is an integer number (775210990).

Almost surely, 2^1550421979 is an apocalyptic number.

1550421979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1550421979 is an equidigital number, since it uses as much as digits as its factorization.

1550421979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 113400, while the sum is 43.

The square root of 1550421979 is about 39375.3981440188. The cubic root of 1550421979 is about 1157.3995400967.

The spelling of 1550421979 in words is "one billion, five hundred fifty million, four hundred twenty-one thousand, nine hundred seventy-nine".