21097477 has 8 divisors (see below), whose sum is σ = 21716640. Its totient is φ = 20484240.

The previous prime is 21097469. The next prime is 21097481. The reversal of 21097477 is 77479012.

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

It is a cyclic number.

It is not a de Polignac number, because 21097477 - 2³ = 21097469 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 (21097457) 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, 6327 + ... + 9067.

It is an arithmetic number, because the mean of its divisors is an integer number (2714580).

Almost surely, 2^21097477 is an apocalyptic number.

It is an amenable number.

21097477 is a deficient number, since it is larger than the sum of its proper divisors (619163).

21097477 is a wasteful number, since it uses less digits than its factorization.

21097477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2963.

The product of its (nonzero) digits is 24696, while the sum is 37.

The square root of 21097477 is about 4593.1989941652. The cubic root of 21097477 is about 276.3186344891.

The spelling of 21097477 in words is "twenty-one million, ninety-seven thousand, four hundred seventy-seven".