21140990 has 16 divisors (see below), whose sum is σ = 40981248. Its totient is φ = 7805856.

The previous prime is 21140957. The next prime is 21141007. The reversal of 21140990 is 9904112.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

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, 81182 + ... + 81441.

It is an arithmetic number, because the mean of its divisors is an integer number (2561328).

Almost surely, 2^21140990 is an apocalyptic number.

21140990 is a deficient number, since it is larger than the sum of its proper divisors (19840258).

21140990 is a wasteful number, since it uses less digits than its factorization.

21140990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162643.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 21140990 is about 4597.9332313551. The cubic root of 21140990 is about 276.5084707142.

The spelling of 21140990 in words is "twenty-one million, one hundred forty thousand, nine hundred ninety".