215405055403251 has 32 divisors (see below), whose sum is σ = 329686441778688. Its totient is φ = 122544804303360.

The previous prime is 215405055403249. The next prime is 215405055403273. The reversal of 215405055403251 is 152304550504512.

It is a happy number.

It is not a de Polignac number, because 215405055403251 - 2¹ = 215405055403249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215405055403151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 448015041 + ... + 448495581.

It is an arithmetic number, because the mean of its divisors is an integer number (10302701305584).

Almost surely, 2^{215405055403251} is an apocalyptic number.

215405055403251 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

215405055403251 is a deficient number, since it is larger than the sum of its proper divisors (114281386375437).

215405055403251 is a wasteful number, since it uses less digits than its factorization.

215405055403251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574811.

The product of its (nonzero) digits is 600000, while the sum is 42.

The spelling of 215405055403251 in words is "two hundred fifteen trillion, four hundred five billion, fifty-five million, four hundred three thousand, two hundred fifty-one".