61521541 has 2 divisors, whose sum is σ = 61521542. Its totient is φ = 61521540.

The previous prime is 61521533. The next prime is 61521569. The reversal of 61521541 is 14512516.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51624225 + 9897316 = 7185^2 + 3146^2 .

It is a cyclic number.

It is not a de Polignac number, because 61521541 - 2³ = 61521533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61521511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30760770 + 30760771.

It is an arithmetic number, because the mean of its divisors is an integer number (30760771).

Almost surely, 2^61521541 is an apocalyptic number.

It is an amenable number.

61521541 is a deficient number, since it is larger than the sum of its proper divisors (1).

61521541 is an equidigital number, since it uses as much as digits as its factorization.

61521541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1200, while the sum is 25.

The square root of 61521541 is about 7843.5668544356. The cubic root of 61521541 is about 394.7684184390.

The spelling of 61521541 in words is "sixty-one million, five hundred twenty-one thousand, five hundred forty-one".