61451320319 has 4 divisors (see below), whose sum is σ = 61477662696. Its totient is φ = 61424977944.

The previous prime is 61451320303. The next prime is 61451320349. The reversal of 61451320319 is 91302315416.

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 61451320319 - 2⁴ = 61451320303 is a prime.

It is a super-2 number, since 2×61451320319² (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 (61451320349) 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, 13167689 + ... + 13172354.

It is an arithmetic number, because the mean of its divisors is an integer number (15369415674).

Almost surely, 2^61451320319 is an apocalyptic number.

61451320319 is a deficient number, since it is larger than the sum of its proper divisors (26342377).

61451320319 is a wasteful number, since it uses less digits than its factorization.

61451320319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26342376.

The product of its (nonzero) digits is 19440, while the sum is 35.

The spelling of 61451320319 in words is "sixty-one billion, four hundred fifty-one million, three hundred twenty thousand, three hundred nineteen".