61358757849 has 45 divisors (see below), whose sum is σ = 97428445807. Its totient is φ = 38475832896.

The previous prime is 61358757809. The next prime is 61358757853. The reversal of 61358757849 is 94875785316.

The square root of 61358757849 is 247707.

It is a perfect power (a square), and thus also a powerful number.

61358757849 is a `hidden beast` number, since 6 + 1 + 3 + 58 + 7 + 578 + 4 + 9 = 666.

61358757849 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 47770659225 + 13588098624 = 218565^2 + 116568^2 .

It is not a de Polignac number, because 61358757849 - 2¹⁵ = 61358725081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61358757809) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 37898362 + ... + 37899980.

Almost surely, 2^61358757849 is an apocalyptic number.

61358757849 is the 247707-th square number.

61358757849 is the 123854-th centered octagonal number.

It is an amenable number.

61358757849 is a deficient number, since it is larger than the sum of its proper divisors (36069687958).

61358757849 is an frugal number, since it uses more digits than its factorization.

61358757849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3284 (or 1639 counting only the distinct ones).

The product of its digits is 50803200, while the sum is 63.

The spelling of 61358757849 in words is "sixty-one billion, three hundred fifty-eight million, seven hundred fifty-seven thousand, eight hundred forty-nine".