1553978641 has 2 divisors, whose sum is σ = 1553978642. Its totient is φ = 1553978640.

The previous prime is 1553978567. The next prime is 1553978681. The reversal of 1553978641 is 1468793551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1310150416 + 243828225 = 36196^2 + 15615^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553978641 - 2²¹ = 1551881489 is a prime.

It is not a weakly prime, because it can be changed into another prime (1553978681) 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, 776989320 + 776989321.

It is an arithmetic number, because the mean of its divisors is an integer number (776989321).

Almost surely, 2^1553978641 is an apocalyptic number.

It is an amenable number.

1553978641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553978641 is an equidigital number, since it uses as much as digits as its factorization.

1553978641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 907200, while the sum is 49.

The square root of 1553978641 is about 39420.5357776883. The cubic root of 1553978641 is about 1158.2838875615.

The spelling of 1553978641 in words is "one billion, five hundred fifty-three million, nine hundred seventy-eight thousand, six hundred forty-one".