21028502 has 8 divisors (see below), whose sum is σ = 34410312. Its totient is φ = 9558400.

The previous prime is 21028493. The next prime is 21028517. The reversal of 21028502 is 20582012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 477899 + ... + 477942.

It is an arithmetic number, because the mean of its divisors is an integer number (4301289).

Almost surely, 2^21028502 is an apocalyptic number.

21028502 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21028502 is a deficient number, since it is larger than the sum of its proper divisors (13381810).

21028502 is a wasteful number, since it uses less digits than its factorization.

21028502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 955854.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 21028502 is about 4585.6844636324. The cubic root of 21028502 is about 276.0171784449.

The spelling of 21028502 in words is "twenty-one million, twenty-eight thousand, five hundred two".