61289880 has 64 divisors (see below), whose sum is σ = 187799040. Its totient is φ = 15994752.

The previous prime is 61289873. The next prime is 61289887. The reversal of 61289880 is 8898216.

It is an interprime number because it is at equal distance from previous prime (61289873) and next prime (61289887).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61289887) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 207 + ... + 11073.

It is an arithmetic number, because the mean of its divisors is an integer number (2934360).

Almost surely, 2^61289880 is an apocalyptic number.

61289880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61289880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93899520).

61289880 is an abundant number, since it is smaller than the sum of its proper divisors (126509160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61289880 is a wasteful number, since it uses less digits than its factorization.

61289880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10928 (or 10924 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 42.

The square root of 61289880 is about 7828.7853463995. The cubic root of 61289880 is about 394.2722915285.

It can be divided in two parts, 61 and 289880, that added together give a triangular number (289941 = T₇₆₁).

The spelling of 61289880 in words is "sixty-one million, two hundred eighty-nine thousand, eight hundred eighty".