61605553 has 2 divisors, whose sum is σ = 61605554. Its totient is φ = 61605552.

The previous prime is 61605539. The next prime is 61605559. The reversal of 61605553 is 35550616.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48121969 + 13483584 = 6937^2 + 3672^2 .

It is a cyclic number.

It is not a de Polignac number, because 61605553 - 2⁵ = 61605521 is a prime.

It is not a weakly prime, because it can be changed into another prime (61605559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30802776 + 30802777.

It is an arithmetic number, because the mean of its divisors is an integer number (30802777).

Almost surely, 2^61605553 is an apocalyptic number.

It is an amenable number.

61605553 is a deficient number, since it is larger than the sum of its proper divisors (1).

61605553 is an equidigital number, since it uses as much as digits as its factorization.

61605553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13500, while the sum is 31.

The square root of 61605553 is about 7848.9204990241. The cubic root of 61605553 is about 394.9480314047.

The spelling of 61605553 in words is "sixty-one million, six hundred five thousand, five hundred fifty-three".