61641521 has 2 divisors, whose sum is σ = 61641522. Its totient is φ = 61641520.

The previous prime is 61641499. The next prime is 61641539. The reversal of 61641521 is 12514616.

61641521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39551521 + 22090000 = 6289^2 + 4700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61641521 is a prime.

It is a super-2 number, since 2×61641521² = 7599354222386882, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61641551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30820760 + 30820761.

It is an arithmetic number, because the mean of its divisors is an integer number (30820761).

Almost surely, 2^61641521 is an apocalyptic number.

It is an amenable number.

61641521 is a deficient number, since it is larger than the sum of its proper divisors (1).

61641521 is an equidigital number, since it uses as much as digits as its factorization.

61641521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 26.

The square root of 61641521 is about 7851.2114351863. The cubic root of 61641521 is about 395.0248790611.

The spelling of 61641521 in words is "sixty-one million, six hundred forty-one thousand, five hundred twenty-one".