16391540 has 24 divisors (see below), whose sum is σ = 37552032. Its totient is φ = 5960480.

The previous prime is 16391539. The next prime is 16391549. The reversal of 16391540 is 4519361.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16391549) 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, 37034 + ... + 37473.

It is an arithmetic number, because the mean of its divisors is an integer number (1564668).

Almost surely, 2^16391540 is an apocalyptic number.

16391540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16391540 is an abundant number, since it is smaller than the sum of its proper divisors (21160492).

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

16391540 is a wasteful number, since it uses less digits than its factorization.

16391540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74527 (or 74525 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 16391540 is about 4048.6466874747. The cubic root of 16391540 is about 254.0231239410.

The spelling of 16391540 in words is "sixteen million, three hundred ninety-one thousand, five hundred forty".