21977057 has 4 divisors (see below), whose sum is σ = 21995520. Its totient is φ = 21958596.

The previous prime is 21977027. The next prime is 21977063. The reversal of 21977057 is 75077912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21977057 - 2¹² = 21972961 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21977057.

It is not an unprimeable number, because it can be changed into a prime (21977027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7313 + ... + 9870.

It is an arithmetic number, because the mean of its divisors is an integer number (5498880).

Almost surely, 2^21977057 is an apocalyptic number.

It is an amenable number.

21977057 is a deficient number, since it is larger than the sum of its proper divisors (18463).

21977057 is a wasteful number, since it uses less digits than its factorization.

21977057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18462.

The product of its (nonzero) digits is 30870, while the sum is 38.

The square root of 21977057 is about 4687.9693898318. The cubic root of 21977057 is about 280.1064943551.

The spelling of 21977057 in words is "twenty-one million, nine hundred seventy-seven thousand, fifty-seven".