21610157 has 8 divisors (see below), whose sum is σ = 22199352. Its totient is φ = 21024000.

The previous prime is 21610151. The next prime is 21610187. The reversal of 21610157 is 75101612.

It can be written as a sum of positive squares in 4 ways, for example, as 4726276 + 16883881 = 2174^2 + 4109^2 .

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 21610157 - 2⁶ = 21610093 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 (21610151) 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, 24203 + ... + 25079.

It is an arithmetic number, because the mean of its divisors is an integer number (2774919).

Almost surely, 2^21610157 is an apocalyptic number.

It is an amenable number.

21610157 is a deficient number, since it is larger than the sum of its proper divisors (589195).

21610157 is an equidigital number, since it uses as much as digits as its factorization.

21610157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1519.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 21610157 is about 4648.6726062393. The cubic root of 21610157 is about 278.5389756002.

Adding to 21610157 its reverse (75101612), we get a palindrome (96711769).

It can be divided in two parts, 216 and 10157, that multiplied together give a palindrome (2193912).

The spelling of 21610157 in words is "twenty-one million, six hundred ten thousand, one hundred fifty-seven".