61669440 has 504 divisors, whose sum is σ = 271028160. Its totient is φ = 12773376.

The previous prime is 61669427. The next prime is 61669441. The reversal of 61669440 is 4496616.

61669440 = 167³ + 168³ + ... + 178³.

It is a tau number, because it is divible by the number of its divisors (504).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 61669395 and 61669404.

It is not an unprimeable number, because it can be changed into a prime (61669441) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2681269 + ... + 2681291.

Almost surely, 2^61669440 is an apocalyptic number.

61669440 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 61669440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135514080).

61669440 is an abundant number, since it is smaller than the sum of its proper divisors (209358720).

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

61669440 is a wasteful number, since it uses less digits than its factorization.

61669440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79 (or 59 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 61669440 is about 7852.9892397736. The cubic root of 61669440 is about 395.0845089706.

The spelling of 61669440 in words is "sixty-one million, six hundred sixty-nine thousand, four hundred forty".