61571813 has 2 divisors, whose sum is σ = 61571814. Its totient is φ = 61571812.

The previous prime is 61571801. The next prime is 61571827. The reversal of 61571813 is 31817516.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61183684 + 388129 = 7822^2 + 623^2 .

It is a cyclic number.

It is not a de Polignac number, because 61571813 - 2⁸ = 61571557 is a prime.

It is a super-2 number, since 2×61571813² = 7582176312213938, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61571813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61571863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30785906 + 30785907.

It is an arithmetic number, because the mean of its divisors is an integer number (30785907).

Almost surely, 2^61571813 is an apocalyptic number.

It is an amenable number.

61571813 is a deficient number, since it is larger than the sum of its proper divisors (1).

61571813 is an equidigital number, since it uses as much as digits as its factorization.

61571813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 32.

The square root of 61571813 is about 7846.7708645022. The cubic root of 61571813 is about 394.8759168016.

The spelling of 61571813 in words is "sixty-one million, five hundred seventy-one thousand, eight hundred thirteen".