61001157581 has 16 divisors (see below), whose sum is σ = 75287520000. Its totient is φ = 48130184448.

The previous prime is 61001157577. The next prime is 61001157593. The reversal of 61001157581 is 18575110016.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 61001157581 - 2² = 61001157577 is a prime.

It is a super-2 number, since 2×61001157581² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61001157181) 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 15 ways as a sum of consecutive naturals, for example, 900956 + ... + 966293.

It is an arithmetic number, because the mean of its divisors is an integer number (4705470000).

Almost surely, 2^61001157581 is an apocalyptic number.

It is an amenable number.

61001157581 is a deficient number, since it is larger than the sum of its proper divisors (14286362419).

61001157581 is a wasteful number, since it uses less digits than its factorization.

61001157581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1867628.

The product of its (nonzero) digits is 8400, while the sum is 35.

Adding to 61001157581 its reverse (18575110016), we get a palindrome (79576267597).

The spelling of 61001157581 in words is "sixty-one billion, one million, one hundred fifty-seven thousand, five hundred eighty-one".