61001553 has 4 divisors (see below), whose sum is σ = 81335408. Its totient is φ = 40667700.

The previous prime is 61001531. The next prime is 61001573. The reversal of 61001553 is 35510016.

It is a happy number.

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.

It is not a de Polignac number, because 61001553 - 2²¹ = 58904401 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61001503) 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, 10166923 + ... + 10166928.

It is an arithmetic number, because the mean of its divisors is an integer number (20333852).

Almost surely, 2^61001553 is an apocalyptic number.

It is an amenable number.

61001553 is a deficient number, since it is larger than the sum of its proper divisors (20333855).

61001553 is a wasteful number, since it uses less digits than its factorization.

61001553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20333854.

The product of its (nonzero) digits is 450, while the sum is 21.

The square root of 61001553 is about 7810.3490959111. The cubic root of 61001553 is about 393.6530589267.

Adding to 61001553 its reverse (35510016), we get a palindrome (96511569).

The spelling of 61001553 in words is "sixty-one million, one thousand, five hundred fifty-three".