61656551 has 8 divisors (see below), whose sum is σ = 69431808. Its totient is φ = 54243000.

The previous prime is 61656547. The next prime is 61656559. The reversal of 61656551 is 15565616.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61656551 - 2² = 61656547 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 (61656559) 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 7 ways as a sum of consecutive naturals, for example, 90065 + ... + 90746.

It is an arithmetic number, because the mean of its divisors is an integer number (8678976).

Almost surely, 2^61656551 is an apocalyptic number.

61656551 is a deficient number, since it is larger than the sum of its proper divisors (7775257).

61656551 is a wasteful number, since it uses less digits than its factorization.

61656551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180853.

The product of its digits is 27000, while the sum is 35.

The square root of 61656551 is about 7852.1685539728. The cubic root of 61656551 is about 395.0569826461.

It can be divided in two parts, 616565 and 51, that added together give a palindrome (616616).

The spelling of 61656551 in words is "sixty-one million, six hundred fifty-six thousand, five hundred fifty-one".