61531517 has 4 divisors (see below), whose sum is σ = 65151036. Its totient is φ = 57912000.

The previous prime is 61531501. The next prime is 61531541. The reversal of 61531517 is 71513516.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18156121 + 43375396 = 4261^2 + 6586^2 .

It is a cyclic number.

It is not a de Polignac number, because 61531517 - 2⁴ = 61531501 is a prime.

It is a super-2 number, since 2×61531517² = 7572255168642578, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61531517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61531117) 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 3 ways as a sum of consecutive naturals, for example, 1809734 + ... + 1809767.

It is an arithmetic number, because the mean of its divisors is an integer number (16287759).

Almost surely, 2^61531517 is an apocalyptic number.

It is an amenable number.

61531517 is a deficient number, since it is larger than the sum of its proper divisors (3619519).

61531517 is a wasteful number, since it uses less digits than its factorization.

61531517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3619518.

The product of its digits is 3150, while the sum is 29.

The square root of 61531517 is about 7844.2027638250. The cubic root of 61531517 is about 394.7897551222.

The spelling of 61531517 in words is "sixty-one million, five hundred thirty-one thousand, five hundred seventeen".