21999475 has 6 divisors (see below), whose sum is σ = 27279380. Its totient is φ = 17599560.

The previous prime is 21999469. The next prime is 21999539. The reversal of 21999475 is 57499912.

It is a happy number.

It is not a de Polignac number, because 21999475 - 2⁵ = 21999443 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 439965 + ... + 440014.

Almost surely, 2^21999475 is an apocalyptic number.

21999475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21999475 is a deficient number, since it is larger than the sum of its proper divisors (5279905).

21999475 is an equidigital number, since it uses as much as digits as its factorization.

21999475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 879989 (or 879984 counting only the distinct ones).

The product of its digits is 204120, while the sum is 46.

The square root of 21999475 is about 4690.3597943015. The cubic root of 21999475 is about 280.2017041529.

The spelling of 21999475 in words is "twenty-one million, nine hundred ninety-nine thousand, four hundred seventy-five".