61997779901 has 8 divisors (see below), whose sum is σ = 63865774944. Its totient is φ = 60139910160.

The previous prime is 61997779861. The next prime is 61997779903. The reversal of 61997779901 is 10997779916.

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

It is a cyclic number.

It is not a de Polignac number, because 61997779901 - 2¹⁴ = 61997763517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61997779903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2518895 + ... + 2543388.

It is an arithmetic number, because the mean of its divisors is an integer number (7983221868).

Almost surely, 2^61997779901 is an apocalyptic number.

It is an amenable number.

61997779901 is a deficient number, since it is larger than the sum of its proper divisors (1867995043).

61997779901 is a wasteful number, since it uses less digits than its factorization.

61997779901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5062651.

The product of its (nonzero) digits is 13502538, while the sum is 65.

The spelling of 61997779901 in words is "sixty-one billion, nine hundred ninety-seven million, seven hundred seventy-nine thousand, nine hundred one".