21357161 has 8 divisors (see below), whose sum is σ = 24496704. Its totient is φ = 18239760.

The previous prime is 21357107. The next prime is 21357191. The reversal of 21357161 is 16175312.

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

It is not a de Polignac number, because 21357161 - 2¹⁴ = 21340777 is a prime.

It is a super-2 number, since 2×21357161² = 912256651959842, which contains 22 as substring.

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 21357161.

It is not an unprimeable number, because it can be changed into a prime (21357101) 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, 3410 + ... + 7371.

It is an arithmetic number, because the mean of its divisors is an integer number (3062088).

Almost surely, 2^21357161 is an apocalyptic number.

It is an amenable number.

21357161 is a deficient number, since it is larger than the sum of its proper divisors (3139543).

21357161 is a wasteful number, since it uses less digits than its factorization.

21357161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11071.

The product of its digits is 1260, while the sum is 26.

The square root of 21357161 is about 4621.3808542469. The cubic root of 21357161 is about 277.4477287039.

The spelling of 21357161 in words is "twenty-one million, three hundred fifty-seven thousand, one hundred sixty-one".