72170840 has 64 divisors (see below), whose sum is σ = 187306560. Its totient is φ = 24514560.

The previous prime is 72170837. The next prime is 72170843. The reversal of 72170840 is 4807127.

It is an interprime number because it is at equal distance from previous prime (72170837) and next prime (72170843).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72170843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30500 + ... + 32780.

It is an arithmetic number, because the mean of its divisors is an integer number (2926665).

Almost surely, 2^72170840 is an apocalyptic number.

72170840 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 72170840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93653280).

72170840 is an abundant number, since it is smaller than the sum of its proper divisors (115135720).

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

72170840 is a wasteful number, since it uses less digits than its factorization.

72170840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2412 (or 2408 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 72170840 is about 8495.3422532585. The cubic root of 72170840 is about 416.3455431526.

Adding to 72170840 its reverse (4807127), we get a palindrome (76977967).

The spelling of 72170840 in words is "seventy-two million, one hundred seventy thousand, eight hundred forty".