21155142253465 has 64 divisors (see below), whose sum is σ = 28711172286720. Its totient is φ = 14828395299840.

The previous prime is 21155142253459. The next prime is 21155142253489. The reversal of 21155142253465 is 56435224155112.

It is a happy number.

It is not a de Polignac number, because 21155142253465 - 2⁹ = 21155142252953 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 996604182 + ... + 996625408.

It is an arithmetic number, because the mean of its divisors is an integer number (448612066980).

Almost surely, 2^{21155142253465} is an apocalyptic number.

It is an amenable number.

21155142253465 is a deficient number, since it is larger than the sum of its proper divisors (7556030033255).

21155142253465 is a wasteful number, since it uses less digits than its factorization.

21155142253465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25882.

The product of its digits is 1440000, while the sum is 46.

The spelling of 21155142253465 in words is "twenty-one trillion, one hundred fifty-five billion, one hundred forty-two million, two hundred fifty-three thousand, four hundred sixty-five".