21693502 has 4 divisors (see below), whose sum is σ = 32540256. Its totient is φ = 10846750.

The previous prime is 21693499. The next prime is 21693509. The reversal of 21693502 is 20539612.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21693509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5423374 + ... + 5423377.

It is an arithmetic number, because the mean of its divisors is an integer number (8135064).

Almost surely, 2^21693502 is an apocalyptic number.

21693502 is a deficient number, since it is larger than the sum of its proper divisors (10846754).

21693502 is a wasteful number, since it uses less digits than its factorization.

21693502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10846753.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 21693502 is about 4657.6283664543. The cubic root of 21693502 is about 278.8966014162.

It can be divided in two parts, 2169 and 3502, that added together give a triangular number (5671 = T₁₀₆).

The spelling of 21693502 in words is "twenty-one million, six hundred ninety-three thousand, five hundred two".