21980455 has 8 divisors (see below), whose sum is σ = 30144672. Its totient is φ = 15072288.

The previous prime is 21980449. The next prime is 21980461. The reversal of 21980455 is 55408912.

It is an interprime number because it is at equal distance from previous prime (21980449) and next prime (21980461).

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

It is not a de Polignac number, because 21980455 - 2³ = 21980447 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21980455.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 313972 + ... + 314041.

It is an arithmetic number, because the mean of its divisors is an integer number (3768084).

Almost surely, 2^21980455 is an apocalyptic number.

21980455 is a deficient number, since it is larger than the sum of its proper divisors (8164217).

21980455 is an equidigital number, since it uses as much as digits as its factorization.

21980455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628025.

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 21980455 is about 4688.3317928662. The cubic root of 21980455 is about 280.1209299066.

The spelling of 21980455 in words is "twenty-one million, nine hundred eighty thousand, four hundred fifty-five".