61438615769 has 4 divisors (see below), whose sum is σ = 61552181220. Its totient is φ = 61325050320.

The previous prime is 61438615759. The next prime is 61438615781. The reversal of 61438615769 is 96751683416.

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 33811854400 + 27626761369 = 183880^2 + 166213^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61438615769 is a prime.

It is a super-2 number, since 2×61438615769² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61438615759) 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, 56781914 + ... + 56782995.

It is an arithmetic number, because the mean of its divisors is an integer number (15388045305).

Almost surely, 2^61438615769 is an apocalyptic number.

It is an amenable number.

61438615769 is a deficient number, since it is larger than the sum of its proper divisors (113565451).

61438615769 is a wasteful number, since it uses less digits than its factorization.

61438615769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113565450.

The product of its digits is 6531840, while the sum is 56.

The spelling of 61438615769 in words is "sixty-one billion, four hundred thirty-eight million, six hundred fifteen thousand, seven hundred sixty-nine".