61640055 has 32 divisors (see below), whose sum is σ = 109912320. Its totient is φ = 32775840.

The previous prime is 61640053. The next prime is 61640057. The reversal of 61640055 is 55004616.

It is a happy number.

61640055 is a `hidden beast` number, since 616 + 40 + 0 + 5 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (61640053) and next prime (61640057).

It is not a de Polignac number, because 61640055 - 2¹ = 61640053 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61640053) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 75600 + ... + 76410.

It is an arithmetic number, because the mean of its divisors is an integer number (3434760).

Almost surely, 2^61640055 is an apocalyptic number.

61640055 is a deficient number, since it is larger than the sum of its proper divisors (48272265).

61640055 is a wasteful number, since it uses less digits than its factorization.

61640055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388 (or 1382 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 61640055 is about 7851.1180732428. The cubic root of 61640055 is about 395.0217474540.

The spelling of 61640055 in words is "sixty-one million, six hundred forty thousand, fifty-five".