71651440 has 80 divisors (see below), whose sum is σ = 198701568. Its totient is φ = 23493888.

The previous prime is 71651423. The next prime is 71651441. The reversal of 71651440 is 4415617.

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 (28).

It is a junction number, because it is equal to n+sod(n) for n = 71651399 and 71651408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71651441) 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, 10099 + ... + 15661.

Almost surely, 2^71651440 is an apocalyptic number.

71651440 is a gapful number since it is divisible by the number (70) 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 71651440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99350784).

71651440 is an abundant number, since it is smaller than the sum of its proper divisors (127050128).

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

71651440 is a wasteful number, since it uses less digits than its factorization.

71651440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5606 (or 5600 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 71651440 is about 8464.7173609046. The cubic root of 71651440 is about 415.3443505693.

It can be divided in two parts, 71 and 651440, that added together give a triangular number (651511 = T₁₁₄₁).

The spelling of 71651440 in words is "seventy-one million, six hundred fifty-one thousand, four hundred forty".