61431988633599 has 4 divisors (see below), whose sum is σ = 81909318178136. Its totient is φ = 40954659089064.

The previous prime is 61431988633579. The next prime is 61431988633643. The reversal of 61431988633599 is 99533688913416.

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

It is not a de Polignac number, because 61431988633599 - 2⁸ = 61431988633343 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 61431988633599.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61431988633579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (37) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10238664772264 + ... + 10238664772269.

It is an arithmetic number, because the mean of its divisors is an integer number (20477329544534).

Almost surely, 2^{61431988633599} is an apocalyptic number.

61431988633599 is a deficient number, since it is larger than the sum of its proper divisors (20477329544537).

61431988633599 is a wasteful number, since it uses less digits than its factorization.

61431988633599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20477329544536.

The product of its digits is 906992640, while the sum is 75.

The spelling of 61431988633599 in words is "sixty-one trillion, four hundred thirty-one billion, nine hundred eighty-eight million, six hundred thirty-three thousand, five hundred ninety-nine".