61901817511 has 4 divisors (see below), whose sum is σ = 65543100912. Its totient is φ = 58260534112.

The previous prime is 61901817503. The next prime is 61901817517. The reversal of 61901817511 is 11571810916.

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

It is a cyclic number.

It is not a de Polignac number, because 61901817511 - 2³ = 61901817503 is a prime.

It is a super-2 number, since 2×61901817511² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61901817517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1820641675 + ... + 1820641708.

It is an arithmetic number, because the mean of its divisors is an integer number (16385775228).

Almost surely, 2^61901817511 is an apocalyptic number.

61901817511 is a deficient number, since it is larger than the sum of its proper divisors (3641283401).

61901817511 is a wasteful number, since it uses less digits than its factorization.

61901817511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3641283400.

The product of its (nonzero) digits is 15120, while the sum is 40.

The spelling of 61901817511 in words is "sixty-one billion, nine hundred one million, eight hundred seventeen thousand, five hundred eleven".