21151023 has 8 divisors (see below), whose sum is σ = 28388736. Its totient is φ = 14007000.

The previous prime is 21150991. The next prime is 21151027. The reversal of 21151023 is 32015112.

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

It is not a de Polignac number, because 21151023 - 2⁵ = 21150991 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21150993 and 21151011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151027) 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, 22893 + ... + 23798.

It is an arithmetic number, because the mean of its divisors is an integer number (3548592).

Almost surely, 2^21151023 is an apocalyptic number.

21151023 is a deficient number, since it is larger than the sum of its proper divisors (7237713).

21151023 is a wasteful number, since it uses less digits than its factorization.

21151023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46845.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21151023 is about 4599.0241356183. The cubic root of 21151023 is about 276.5522051963.

Adding to 21151023 its reverse (32015112), we get a palindrome (53166135).

The spelling of 21151023 in words is "twenty-one million, one hundred fifty-one thousand, twenty-three".