21850501 has 4 divisors (see below), whose sum is σ = 21971404. Its totient is φ = 21729600.

The previous prime is 21850489. The next prime is 21850547. The reversal of 21850501 is 10505812.

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 181476 + 21669025 = 426^2 + 4655^2 .

It is a cyclic number.

It is not a de Polignac number, because 21850501 - 2¹³ = 21842309 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21850901) 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, 60180 + ... + 60541.

It is an arithmetic number, because the mean of its divisors is an integer number (5492851).

Almost surely, 2^21850501 is an apocalyptic number.

It is an amenable number.

21850501 is a deficient number, since it is larger than the sum of its proper divisors (120903).

21850501 is a wasteful number, since it uses less digits than its factorization.

21850501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120902.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 21850501 is about 4674.4519464853. The cubic root of 21850501 is about 279.5677898129.

The spelling of 21850501 in words is "twenty-one million, eight hundred fifty thousand, five hundred one".