21098994 has 32 divisors (see below), whose sum is σ = 48362496. Its totient is φ = 6011280.

The previous prime is 21098951. The next prime is 21099007. The reversal of 21098994 is 49989012.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

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, 28659 + ... + 29385.

It is an arithmetic number, because the mean of its divisors is an integer number (1511328).

Almost surely, 2^21098994 is an apocalyptic number.

21098994 is an abundant number, since it is smaller than the sum of its proper divisors (27263502).

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

21098994 is a wasteful number, since it uses less digits than its factorization.

21098994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1430.

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 21098994 is about 4593.3641266505. The cubic root of 21098994 is about 276.3252571660.

The spelling of 21098994 in words is "twenty-one million, ninety-eight thousand, nine hundred ninety-four".