21951369 has 24 divisors (see below), whose sum is σ = 36627552. Its totient is φ = 12520320.

The previous prime is 21951367. The next prime is 21951383. The reversal of 21951369 is 96315912.

It is not a de Polignac number, because 21951369 - 2¹ = 21951367 is a prime.

It is a super-2 number, since 2×21951369² = 963725201948322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21951367) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4839 + ... + 8204.

It is an arithmetic number, because the mean of its divisors is an integer number (1526148).

Almost surely, 2^21951369 is an apocalyptic number.

It is an amenable number.

21951369 is a deficient number, since it is larger than the sum of its proper divisors (14676183).

21951369 is a wasteful number, since it uses less digits than its factorization.

21951369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13077 (or 13074 counting only the distinct ones).

The product of its digits is 14580, while the sum is 36.

The square root of 21951369 is about 4685.2288097808. The cubic root of 21951369 is about 279.9973171512.

The spelling of 21951369 in words is "twenty-one million, nine hundred fifty-one thousand, three hundred sixty-nine".