61405551 has 6 divisors (see below), whose sum is σ = 88696920. Its totient is φ = 40937028.

The previous prime is 61405541. The next prime is 61405579. The reversal of 61405551 is 15550416.

It is a happy number.

It is not a de Polignac number, because 61405551 - 2¹³ = 61397359 is a prime.

It is a super-2 number, since 2×61405551² = 7541283387227202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61405541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3411411 + ... + 3411428.

It is an arithmetic number, because the mean of its divisors is an integer number (14782820).

Almost surely, 2^61405551 is an apocalyptic number.

61405551 is a deficient number, since it is larger than the sum of its proper divisors (27291369).

61405551 is a wasteful number, since it uses less digits than its factorization.

61405551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6822845 (or 6822842 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The square root of 61405551 is about 7836.1694085822. The cubic root of 61405551 is about 394.5201693727.

Adding to 61405551 its reverse (15550416), we get a palindrome (76955967).

The spelling of 61405551 in words is "sixty-one million, four hundred five thousand, five hundred fifty-one".