71987490 has 48 divisors (see below), whose sum is σ = 189748728. Its totient is φ = 18931968.

The previous prime is 71987471. The next prime is 71987491. The reversal of 71987490 is 9478917.

71987490 is a `hidden beast` number, since 71 + 98 + 7 + 490 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 62678889 + 9308601 = 7917^2 + 3051^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (71987491) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1092 + ... + 12048.

Almost surely, 2^71987490 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71987490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94874364).

71987490 is an abundant number, since it is smaller than the sum of its proper divisors (117761238).

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

71987490 is a wasteful number, since it uses less digits than its factorization.

71987490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11043 (or 11040 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The square root of 71987490 is about 8484.5441833961. The cubic root of 71987490 is about 415.9926689105.

It can be divided in two parts, 719 and 87490, that added together give a square (88209 = 297²).

The spelling of 71987490 in words is "seventy-one million, nine hundred eighty-seven thousand, four hundred ninety".