16121540 has 48 divisors (see below), whose sum is σ = 35163072. Its totient is φ = 6205056.

The previous prime is 16121537. The next prime is 16121561. The reversal of 16121540 is 4512161.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70907 + ... + 71133.

It is an arithmetic number, because the mean of its divisors is an integer number (732564).

Almost surely, 2^16121540 is an apocalyptic number.

16121540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16121540 is an abundant number, since it is smaller than the sum of its proper divisors (19041532).

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

16121540 is a wasteful number, since it uses less digits than its factorization.

16121540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 16121540 is about 4015.1637575571. The cubic root of 16121540 is about 252.6206461978.

It can be divided in two parts, 16121 and 540, that added together give a palindrome (16661).

The spelling of 16121540 in words is "sixteen million, one hundred twenty-one thousand, five hundred forty".