21262993 has 8 divisors (see below), whose sum is σ = 22014720. Its totient is φ = 20515440.

The previous prime is 21262979. The next prime is 21262999. The reversal of 21262993 is 39926212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21262993 is a prime.

It is a super-2 number, since 2×21262993² = 904229742636098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21262999) 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, 12171 + ... + 13807.

It is an arithmetic number, because the mean of its divisors is an integer number (2751840).

Almost surely, 2^21262993 is an apocalyptic number.

It is an amenable number.

21262993 is a deficient number, since it is larger than the sum of its proper divisors (751727).

21262993 is a wasteful number, since it uses less digits than its factorization.

21262993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2087.

The product of its digits is 11664, while the sum is 34.

The square root of 21262993 is about 4611.1813020093. The cubic root of 21262993 is about 277.0393537122.

The spelling of 21262993 in words is "twenty-one million, two hundred sixty-two thousand, nine hundred ninety-three".