61857749 has 4 divisors (see below), whose sum is σ = 65113440. Its totient is φ = 58602060.

The previous prime is 61857739. The next prime is 61857751. The reversal of 61857749 is 94775816.

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 a cyclic number.

It is not a de Polignac number, because 61857749 - 2²⁰ = 60809173 is a prime.

It is a super-2 number, since 2×61857749² = 7652762222694002, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61857739) 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, 1627817 + ... + 1627854.

It is an arithmetic number, because the mean of its divisors is an integer number (16278360).

Almost surely, 2^61857749 is an apocalyptic number.

It is an amenable number.

61857749 is a deficient number, since it is larger than the sum of its proper divisors (3255691).

61857749 is a wasteful number, since it uses less digits than its factorization.

61857749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3255690.

The product of its digits is 423360, while the sum is 47.

The square root of 61857749 is about 7864.9697392933. The cubic root of 61857749 is about 395.4862334537.

The spelling of 61857749 in words is "sixty-one million, eight hundred fifty-seven thousand, seven hundred forty-nine".