61533245621 has 2 divisors, whose sum is σ = 61533245622. Its totient is φ = 61533245620.

The previous prime is 61533245603. The next prime is 61533245693. The reversal of 61533245621 is 12654233516.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39527006596 + 22006239025 = 198814^2 + 148345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61533245621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61533242621) 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, 30766622810 + 30766622811.

It is an arithmetic number, because the mean of its divisors is an integer number (30766622811).

Almost surely, 2^61533245621 is an apocalyptic number.

It is an amenable number.

61533245621 is a deficient number, since it is larger than the sum of its proper divisors (1).

61533245621 is an equidigital number, since it uses as much as digits as its factorization.

61533245621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 38.

The spelling of 61533245621 in words is "sixty-one billion, five hundred thirty-three million, two hundred forty-five thousand, six hundred twenty-one".