20976451 has 4 divisors (see below), whose sum is σ = 20986992. Its totient is φ = 20965912.

The previous prime is 20976433. The next prime is 20976457. The reversal of 20976451 is 15467902.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 15467902 = 2 ⋅7733951.

It is a cyclic number.

It is not a de Polignac number, because 20976451 - 2⁹ = 20975939 is a prime.

It is a super-2 number, since 2×20976451² = 880022993110802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20976457) 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, 1276 + ... + 6601.

It is an arithmetic number, because the mean of its divisors is an integer number (5246748).

Almost surely, 2^20976451 is an apocalyptic number.

20976451 is a deficient number, since it is larger than the sum of its proper divisors (10541).

20976451 is an equidigital number, since it uses as much as digits as its factorization.

20976451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10540.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20976451 is about 4580.0055676822. The cubic root of 20976451 is about 275.7892522319.

The spelling of 20976451 in words is "twenty million, nine hundred seventy-six thousand, four hundred fifty-one".