16391890 has 16 divisors (see below), whose sum is σ = 29740032. Its totient is φ = 6504624.

The previous prime is 16391887. The next prime is 16391909. The reversal of 16391890 is 9819361.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5184 + ... + 7723.

It is an arithmetic number, because the mean of its divisors is an integer number (1858752).

Almost surely, 2^16391890 is an apocalyptic number.

16391890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16391890 is a deficient number, since it is larger than the sum of its proper divisors (13348142).

16391890 is a wasteful number, since it uses less digits than its factorization.

16391890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13041.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 16391890 is about 4048.6899115640. The cubic root of 16391890 is about 254.0249319359.

The spelling of 16391890 in words is "sixteen million, three hundred ninety-one thousand, eight hundred ninety".