61987440 has 80 divisors (see below), whose sum is σ = 203478048. Its totient is φ = 15556608.

The previous prime is 61987421. The next prime is 61987441. The reversal of 61987440 is 4478916.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61987441) 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, 3517 + ... + 11676.

Almost surely, 2^61987440 is an apocalyptic number.

61987440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61987440 is an abundant number, since it is smaller than the sum of its proper divisors (141490608).

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

61987440 is a wasteful number, since it uses less digits than its factorization.

61987440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15226 (or 15220 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 61987440 is about 7873.2102728176. The cubic root of 61987440 is about 395.7624327552.

The spelling of 61987440 in words is "sixty-one million, nine hundred eighty-seven thousand, four hundred forty".