21980451 has 8 divisors (see below), whose sum is σ = 29368000. Its totient is φ = 14623272.

The previous prime is 21980449. The next prime is 21980461. The reversal of 21980451 is 15408912.

It is a happy number.

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

It is not a de Polignac number, because 21980451 - 2¹ = 21980449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21980401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5845 + ... + 8838.

It is an arithmetic number, because the mean of its divisors is an integer number (3671000).

Almost surely, 2^21980451 is an apocalyptic number.

21980451 is a deficient number, since it is larger than the sum of its proper divisors (7387549).

21980451 is a wasteful number, since it uses less digits than its factorization.

21980451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15185.

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 21980451 is about 4688.3313662752. The cubic root of 21980451 is about 280.1209129145.

The spelling of 21980451 in words is "twenty-one million, nine hundred eighty thousand, four hundred fifty-one".