21999753 has 12 divisors (see below), whose sum is σ = 33159360. Its totient is φ = 14028696.

The previous prime is 21999737. The next prime is 21999763. The reversal of 21999753 is 35799912.

It is a happy number.

It is not a de Polignac number, because 21999753 - 2⁴ = 21999737 is a prime.

It is a super-2 number, since 2×21999753² = 967978264122018, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21999699 and 21999708.

It is not an unprimeable number, because it can be changed into a prime (21999763) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52933 + ... + 53346.

It is an arithmetic number, because the mean of its divisors is an integer number (2763280).

Almost surely, 2^21999753 is an apocalyptic number.

21999753 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21999753 is a deficient number, since it is larger than the sum of its proper divisors (11159607).

21999753 is a wasteful number, since it uses less digits than its factorization.

21999753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106308 (or 106305 counting only the distinct ones).

The product of its digits is 153090, while the sum is 45.

The square root of 21999753 is about 4690.3894294611. The cubic root of 21999753 is about 280.2028844196.

The spelling of 21999753 in words is "twenty-one million, nine hundred ninety-nine thousand, seven hundred fifty-three".