61655409 has 6 divisors (see below), whose sum is σ = 89057826. Its totient is φ = 41103600.

The previous prime is 61655401. The next prime is 61655417. The reversal of 61655409 is 90455616.

It is an interprime number because it is at equal distance from previous prime (61655401) and next prime (61655417).

It can be written as a sum of positive squares in only one way, i.e., 60840000 + 815409 = 7800^2 + 903^2 .

It is not a de Polignac number, because 61655409 - 2³ = 61655401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61655401) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3425292 + ... + 3425309.

It is an arithmetic number, because the mean of its divisors is an integer number (14842971).

Almost surely, 2^61655409 is an apocalyptic number.

It is an amenable number.

61655409 is a deficient number, since it is larger than the sum of its proper divisors (27402417).

61655409 is a wasteful number, since it uses less digits than its factorization.

61655409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6850607 (or 6850604 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 61655409 is about 7852.0958348711. The cubic root of 61655409 is about 395.0545435549.

The spelling of 61655409 in words is "sixty-one million, six hundred fifty-five thousand, four hundred nine".