61597861 has 16 divisors (see below), whose sum is σ = 67964400. Its totient is φ = 55480320.

The previous prime is 61597831. The next prime is 61597873. The reversal of 61597861 is 16879516.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 2461761 + 59136100 = 1569^2 + 7690^2 .

It is a cyclic number.

It is not a de Polignac number, because 61597861 - 2¹¹ = 61595813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61597831) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136965 + ... + 137413.

It is an arithmetic number, because the mean of its divisors is an integer number (4247775).

Almost surely, 2^61597861 is an apocalyptic number.

61597861 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

61597861 is a deficient number, since it is larger than the sum of its proper divisors (6366539).

61597861 is a wasteful number, since it uses less digits than its factorization.

61597861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696.

The product of its digits is 90720, while the sum is 43.

The square root of 61597861 is about 7848.4304800387. The cubic root of 61597861 is about 394.9315931317.

It can be divided in two parts, 61 and 597861, that multiplied together give a square (36469521 = 6039²).

The spelling of 61597861 in words is "sixty-one million, five hundred ninety-seven thousand, eight hundred sixty-one".