61899699817 has 4 divisors (see below), whose sum is σ = 61917394000. Its totient is φ = 61882005636.

The previous prime is 61899699793. The next prime is 61899699847. The reversal of 61899699817 is 71899699816.

61899699817 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61899699817 - 2¹⁹ = 61899175529 is a prime.

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 61899699817.

It is not an unprimeable number, because it can be changed into a prime (61899699847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8841843 + ... + 8848840.

It is an arithmetic number, because the mean of its divisors is an integer number (15479348500).

Almost surely, 2^61899699817 is an apocalyptic number.

It is an amenable number.

61899699817 is a deficient number, since it is larger than the sum of its proper divisors (17694183).

61899699817 is a wasteful number, since it uses less digits than its factorization.

61899699817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17694182.

The product of its digits is 105815808, while the sum is 73.

Subtracting 61899699817 from its reverse (71899699816), we obtain a palindrome (9999999999).

The spelling of 61899699817 in words is "sixty-one billion, eight hundred ninety-nine million, six hundred ninety-nine thousand, eight hundred seventeen".