78061261 has 4 divisors (see below), whose sum is σ = 78310972. Its totient is φ = 77811552.

The previous prime is 78061237. The next prime is 78061271. The reversal of 78061261 is 16216087.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16216087 = 1973 ⋅8219.

It can be written as a sum of positive squares in 2 ways, for example, as 17065161 + 60996100 = 4131^2 + 7810^2 .

It is a cyclic number.

It is not a de Polignac number, because 78061261 - 2¹⁵ = 78028493 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 (78061271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124386 + ... + 125011.

It is an arithmetic number, because the mean of its divisors is an integer number (19577743).

Almost surely, 2^78061261 is an apocalyptic number.

It is an amenable number.

78061261 is a deficient number, since it is larger than the sum of its proper divisors (249711).

78061261 is a wasteful number, since it uses less digits than its factorization.

78061261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249710.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 78061261 is about 8835.2284067816. The cubic root of 78061261 is about 427.3776967374.

The spelling of 78061261 in words is "seventy-eight million, sixty-one thousand, two hundred sixty-one".