61521551 has 8 divisors (see below), whose sum is σ = 75718944. Its totient is φ = 48676320.

The previous prime is 61521541. The next prime is 61521569. The reversal of 61521551 is 15512516.

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

It is a de Polignac number, because none of the positive numbers 2^k-61521551 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61521551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61521511) 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, 337940 + ... + 338121.

It is an arithmetic number, because the mean of its divisors is an integer number (9464868).

Almost surely, 2^61521551 is an apocalyptic number.

61521551 is a deficient number, since it is larger than the sum of its proper divisors (14197393).

61521551 is a wasteful number, since it uses less digits than its factorization.

61521551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 676081.

The product of its digits is 1500, while the sum is 26.

The square root of 61521551 is about 7843.5674919006. The cubic root of 61521551 is about 394.7684398282.

The spelling of 61521551 in words is "sixty-one million, five hundred twenty-one thousand, five hundred fifty-one".