21149154 has 64 divisors (see below), whose sum is σ = 51770880. Its totient is φ = 6359040.

The previous prime is 21149131. The next prime is 21149171. The reversal of 21149154 is 45194112.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32674 + ... + 33314.

It is an arithmetic number, because the mean of its divisors is an integer number (808920).

Almost surely, 2^21149154 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21149154, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25885440).

21149154 is an abundant number, since it is smaller than the sum of its proper divisors (30621726).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21149154 is a wasteful number, since it uses less digits than its factorization.

21149154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712 (or 706 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 21149154 is about 4598.8209358487. The cubic root of 21149154 is about 276.5440591554.

The spelling of 21149154 in words is "twenty-one million, one hundred forty-nine thousand, one hundred fifty-four".