61539553 has 2 divisors, whose sum is σ = 61539554. Its totient is φ = 61539552.

The previous prime is 61539539. The next prime is 61539581. The reversal of 61539553 is 35593516.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55249489 + 6290064 = 7433^2 + 2508^2 .

It is a cyclic number.

It is not a de Polignac number, because 61539553 - 2⁵ = 61539521 is a prime.

It is not a weakly prime, because it can be changed into another prime (61539503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30769776 + 30769777.

It is an arithmetic number, because the mean of its divisors is an integer number (30769777).

Almost surely, 2^61539553 is an apocalyptic number.

It is an amenable number.

61539553 is a deficient number, since it is larger than the sum of its proper divisors (1).

61539553 is an equidigital number, since it uses as much as digits as its factorization.

61539553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60750, while the sum is 37.

The square root of 61539553 is about 7844.7149725149. The cubic root of 61539553 is about 394.8069408537.

The spelling of 61539553 in words is "sixty-one million, five hundred thirty-nine thousand, five hundred fifty-three".