20691315 has 16 divisors (see below), whose sum is σ = 36784800. Its totient is φ = 11035296.

The previous prime is 20691311. The next prime is 20691331. The reversal of 20691315 is 51319602.

It is not a de Polignac number, because 20691315 - 2² = 20691311 is a prime.

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

It is not an unprimeable number, because it can be changed into a prime (20691311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76500 + ... + 76769.

It is an arithmetic number, because the mean of its divisors is an integer number (2299050).

Almost surely, 2^20691315 is an apocalyptic number.

20691315 is a deficient number, since it is larger than the sum of its proper divisors (16093485).

20691315 is a wasteful number, since it uses less digits than its factorization.

20691315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153283 (or 153277 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 20691315 is about 4548.7707130608. The cubic root of 20691315 is about 274.5339323218.

The spelling of 20691315 in words is "twenty million, six hundred ninety-one thousand, three hundred fifteen".