4001520 has 40 divisors (see below), whose sum is σ = 12405456. Its totient is φ = 1067008.

The previous prime is 4001509. The next prime is 4001521. The reversal of 4001520 is 251004.

4001520 = 338² + 339² + ... + 369².

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 4001496 and 4001505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4001521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8097 + ... + 8576.

Almost surely, 2^4001520 is an apocalyptic number.

4001520 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

4001520 is an abundant number, since it is smaller than the sum of its proper divisors (8403936).

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

4001520 is a wasteful number, since it uses less digits than its factorization.

4001520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16689 (or 16683 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 4001520 is about 2000.3799639069. The cubic root of 4001520 is about 158.7602097305.

Adding to 4001520 its reverse (251004), we get a palindrome (4252524).

The spelling of 4001520 in words is "four million, one thousand, five hundred twenty".