61540992477 has 24 divisors (see below), whose sum is σ = 94400889336. Its totient is φ = 38499342336.

The previous prime is 61540992451. The next prime is 61540992509. The reversal of 61540992477 is 77429904516.

61540992477 is a `hidden beast` number, since 6 + 1 + 540 + 9 + 9 + 24 + 77 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 25800711876 + 35740280601 = 160626^2 + 189051^2 .

It is not a de Polignac number, because 61540992477 - 2⁶ = 61540992413 is a prime.

It is a super-3 number, since 3×61540992477³ (a number of 33 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61540992407) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 545218 + ... + 648339.

It is an arithmetic number, because the mean of its divisors is an integer number (3933370389).

Almost surely, 2^61540992477 is an apocalyptic number.

It is an amenable number.

61540992477 is a deficient number, since it is larger than the sum of its proper divisors (32859896859).

61540992477 is a wasteful number, since it uses less digits than its factorization.

61540992477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193917 (or 1193914 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 54.

The spelling of 61540992477 in words is "sixty-one billion, five hundred forty million, nine hundred ninety-two thousand, four hundred seventy-seven".