61561477 has 2 divisors, whose sum is σ = 61561478. Its totient is φ = 61561476.

The previous prime is 61561447. The next prime is 61561481. The reversal of 61561477 is 77416516.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61449921 + 111556 = 7839^2 + 334^2 .

It is a cyclic number.

It is not a de Polignac number, because 61561477 - 2²³ = 53172869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61561417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30780738 + 30780739.

It is an arithmetic number, because the mean of its divisors is an integer number (30780739).

Almost surely, 2^61561477 is an apocalyptic number.

It is an amenable number.

61561477 is a deficient number, since it is larger than the sum of its proper divisors (1).

61561477 is an equidigital number, since it uses as much as digits as its factorization.

61561477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 37.

The square root of 61561477 is about 7846.1122219861. The cubic root of 61561477 is about 394.8538197538.

The spelling of 61561477 in words is "sixty-one million, five hundred sixty-one thousand, four hundred seventy-seven".