1553413621 has 2 divisors, whose sum is σ = 1553413622. Its totient is φ = 1553413620.

The previous prime is 1553413613. The next prime is 1553413639. The reversal of 1553413621 is 1263143551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 854392900 + 699020721 = 29230^2 + 26439^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553413621 - 2³ = 1553413613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1553413601) 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, 776706810 + 776706811.

It is an arithmetic number, because the mean of its divisors is an integer number (776706811).

Almost surely, 2^1553413621 is an apocalyptic number.

It is an amenable number.

1553413621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553413621 is an equidigital number, since it uses as much as digits as its factorization.

1553413621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10800, while the sum is 31.

The square root of 1553413621 is about 39413.3685568742. The cubic root of 1553413621 is about 1158.1434881850.

The spelling of 1553413621 in words is "one billion, five hundred fifty-three million, four hundred thirteen thousand, six hundred twenty-one".