21019370 has 16 divisors (see below), whose sum is σ = 37916640. Its totient is φ = 8389584.

The previous prime is 21019363. The next prime is 21019373. The reversal of 21019370 is 7391012.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21019373) 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, 3221 + ... + 7239.

It is an arithmetic number, because the mean of its divisors is an integer number (2369790).

Almost surely, 2^21019370 is an apocalyptic number.

21019370 is a deficient number, since it is larger than the sum of its proper divisors (16897270).

21019370 is a wasteful number, since it uses less digits than its factorization.

21019370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4549.

The product of its (nonzero) digits is 378, while the sum is 23.

The square root of 21019370 is about 4584.6886480981. The cubic root of 21019370 is about 275.9772175412.

The spelling of 21019370 in words is "twenty-one million, nineteen thousand, three hundred seventy".