61805421 has 12 divisors (see below), whose sum is σ = 94526172. Its totient is φ = 38779776.

The previous prime is 61805411. The next prime is 61805431. The reversal of 61805421 is 12450816.

61805421 is a `hidden beast` number, since 618 + 0 + 5 + 42 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (61805411) and next prime (61805431).

It can be written as a sum of positive squares in 2 ways, for example, as 21622500 + 40182921 = 4650^2 + 6339^2 .

It is not a de Polignac number, because 61805421 - 2⁵ = 61805389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61805411) 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, 201826 + ... + 202131.

It is an arithmetic number, because the mean of its divisors is an integer number (7877181).

Almost surely, 2^61805421 is an apocalyptic number.

It is an amenable number.

61805421 is a deficient number, since it is larger than the sum of its proper divisors (32720751).

61805421 is a wasteful number, since it uses less digits than its factorization.

61805421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403980 (or 403977 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 61805421 is about 7861.6423856596. The cubic root of 61805421 is about 395.3746826656.

It can be divided in two parts, 61805 and 421, that added together give a palindrome (62226).

The spelling of 61805421 in words is "sixty-one million, eight hundred five thousand, four hundred twenty-one".