61401965805 has 12 divisors (see below), whose sum is σ = 106430074140. Its totient is φ = 32747715072.

The previous prime is 61401965803. The next prime is 61401965837. The reversal of 61401965805 is 50856910416.

61401965805 is a `hidden beast` number, since 61 + 4 + 0 + 1 + 9 + 6 + 580 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7365244041 + 54036721764 = 85821^2 + 232458^2 .

It is not a de Polignac number, because 61401965805 - 2¹ = 61401965803 is a prime.

It is a super-3 number, since 3×61401965805³ (a number of 33 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 1364488129 = 61401965805 / (6 + 1 + 4 + 0 + 1 + 9 + 6 + 5 + 8 + 0 + 5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61401965803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 682244020 + ... + 682244109.

It is an arithmetic number, because the mean of its divisors is an integer number (8869172845).

Almost surely, 2^61401965805 is an apocalyptic number.

It is an amenable number.

61401965805 is a deficient number, since it is larger than the sum of its proper divisors (45028108335).

61401965805 is a wasteful number, since it uses less digits than its factorization.

61401965805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1364488140 (or 1364488137 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The spelling of 61401965805 in words is "sixty-one billion, four hundred one million, nine hundred sixty-five thousand, eight hundred five".