1621625513 has 2 divisors, whose sum is σ = 1621625514. Its totient is φ = 1621625512.

The previous prime is 1621625507. The next prime is 1621625521. The reversal of 1621625513 is 3155261261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1192182784 + 429442729 = 34528^2 + 20723^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621625513 - 2¹⁰ = 1621624489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1621625513.

It is not a weakly prime, because it can be changed into another prime (1621625543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810812756 + 810812757.

It is an arithmetic number, because the mean of its divisors is an integer number (810812757).

Almost surely, 2^1621625513 is an apocalyptic number.

It is an amenable number.

1621625513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621625513 is an equidigital number, since it uses as much as digits as its factorization.

1621625513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10800, while the sum is 32.

The square root of 1621625513 is about 40269.4116296725. The cubic root of 1621625513 is about 1174.8529800660.

Adding to 1621625513 its reverse (3155261261), we get a palindrome (4776886774).

The spelling of 1621625513 in words is "one billion, six hundred twenty-one million, six hundred twenty-five thousand, five hundred thirteen".