74201581561 has 4 divisors (see below), whose sum is σ = 74203319952. Its totient is φ = 74199843172.

The previous prime is 74201581541. The next prime is 74201581577. The reversal of 74201581561 is 16518510247.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16518510247 = 277 ⋅59633611.

It is a cyclic number.

It is not a de Polignac number, because 74201581561 - 2¹⁷ = 74201450489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (74201581501) 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, 803515 + ... + 891088.

It is an arithmetic number, because the mean of its divisors is an integer number (18550829988).

Almost surely, 2^74201581561 is an apocalyptic number.

It is an amenable number.

74201581561 is a deficient number, since it is larger than the sum of its proper divisors (1738391).

74201581561 is a wasteful number, since it uses less digits than its factorization.

74201581561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1738390.

The product of its (nonzero) digits is 67200, while the sum is 40.

The spelling of 74201581561 in words is "seventy-four billion, two hundred one million, five hundred eighty-one thousand, five hundred sixty-one".