21996477 has 12 divisors (see below), whose sum is σ = 31813600. Its totient is φ = 14645448.

The previous prime is 21996473. The next prime is 21996493. The reversal of 21996477 is 77469912.

It is not a de Polignac number, because 21996477 - 2² = 21996473 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21996473) 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, 11718 + ... + 13464.

Almost surely, 2^21996477 is an apocalyptic number.

It is an amenable number.

21996477 is a deficient number, since it is larger than the sum of its proper divisors (9817123).

21996477 is a wasteful number, since it uses less digits than its factorization.

21996477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3152 (or 3149 counting only the distinct ones).

The product of its digits is 190512, while the sum is 45.

The square root of 21996477 is about 4690.0401917254. The cubic root of 21996477 is about 280.1889753208.

The spelling of 21996477 in words is "twenty-one million, nine hundred ninety-six thousand, four hundred seventy-seven".