87720240 has 80 divisors (see below), whose sum is σ = 273027168. Its totient is φ = 23298048.

The previous prime is 87720239. The next prime is 87720263. The reversal of 87720240 is 4202778.

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

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 87720198 and 87720207.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75504 + ... + 76656.

Almost surely, 2^87720240 is an apocalyptic number.

87720240 is a gapful number since it is divisible by the number (80) 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 87720240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136513584).

87720240 is an abundant number, since it is smaller than the sum of its proper divisors (185306928).

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

87720240 is a wasteful number, since it uses less digits than its factorization.

87720240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1486 (or 1480 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 30.

The square root of 87720240 is about 9365.9083916084. The cubic root of 87720240 is about 444.3241687502.

The spelling of 87720240 in words is "eighty-seven million, seven hundred twenty thousand, two hundred forty".