1554780121 has 2 divisors, whose sum is σ = 1554780122. Its totient is φ = 1554780120.

The previous prime is 1554780109. The next prime is 1554780131. The reversal of 1554780121 is 1210874551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1148193225 + 406586896 = 33885^2 + 20164^2 .

It is an emirp because it is prime and its reverse (1210874551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1554780121 - 2⁹ = 1554779609 is a prime.

It is not a weakly prime, because it can be changed into another prime (1554780131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 777390060 + 777390061.

It is an arithmetic number, because the mean of its divisors is an integer number (777390061).

Almost surely, 2^1554780121 is an apocalyptic number.

It is an amenable number.

1554780121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1554780121 is an equidigital number, since it uses as much as digits as its factorization.

1554780121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11200, while the sum is 34.

The square root of 1554780121 is about 39430.7002347156. The cubic root of 1554780121 is about 1158.4829854965.

The spelling of 1554780121 in words is "one billion, five hundred fifty-four million, seven hundred eighty thousand, one hundred twenty-one".