21150601 has 4 divisors (see below), whose sum is σ = 22394772. Its totient is φ = 19906432.

The previous prime is 21150523. The next prime is 21150607. The reversal of 21150601 is 10605112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12418576 + 8732025 = 3524^2 + 2955^2 .

It is a cyclic number.

It is not a de Polignac number, because 21150601 - 2¹⁹ = 20626313 is a prime.

It is a super-2 number, since 2×21150601² = 894695845322402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21150607) 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, 622060 + ... + 622093.

It is an arithmetic number, because the mean of its divisors is an integer number (5598693).

Almost surely, 2^21150601 is an apocalyptic number.

It is an amenable number.

21150601 is a deficient number, since it is larger than the sum of its proper divisors (1244171).

21150601 is a wasteful number, since it uses less digits than its factorization.

21150601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244170.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 21150601 is about 4598.9782560912. The cubic root of 21150601 is about 276.5503659502.

Adding to 21150601 its reverse (10605112), we get a palindrome (31755713).

The spelling of 21150601 in words is "twenty-one million, one hundred fifty thousand, six hundred one".