61638480 has 120 divisors (see below), whose sum is σ = 210656160. Its totient is φ = 16147200.

The previous prime is 61638461. The next prime is 61638491. The reversal of 61638480 is 8483616.

It is a happy number.

61638480 is a `hidden beast` number, since 616 + 38 + 4 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41755 + ... + 43205.

It is an arithmetic number, because the mean of its divisors is an integer number (1755468).

Almost surely, 2^61638480 is an apocalyptic number.

61638480 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 61638480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105328080).

61638480 is an abundant number, since it is smaller than the sum of its proper divisors (149017680).

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

61638480 is a wasteful number, since it uses less digits than its factorization.

61638480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1529 (or 1520 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 61638480 is about 7851.0177684170. The cubic root of 61638480 is about 395.0183829505.

The spelling of 61638480 in words is "sixty-one million, six hundred thirty-eight thousand, four hundred eighty".