61387755 has 32 divisors (see below), whose sum is σ = 115395840. Its totient is φ = 27473280.

The previous prime is 61387747. The next prime is 61387763. The reversal of 61387755 is 55778316.

It is an interprime number because it is at equal distance from previous prime (61387747) and next prime (61387763).

It is not a de Polignac number, because 61387755 - 2³ = 61387747 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12165 + ... + 16454.

It is an arithmetic number, because the mean of its divisors is an integer number (3606120).

Almost surely, 2^61387755 is an apocalyptic number.

61387755 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

61387755 is a deficient number, since it is larger than the sum of its proper divisors (54008085).

61387755 is a wasteful number, since it uses less digits than its factorization.

61387755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28651.

The product of its digits is 176400, while the sum is 42.

The square root of 61387755 is about 7835.0338225179. The cubic root of 61387755 is about 394.4820536043.

The spelling of 61387755 in words is "sixty-one million, three hundred eighty-seven thousand, seven hundred fifty-five".