428431955491 has 32 divisors (see below), whose sum is σ = 471242393600. Its totient is φ = 387991296000.

The previous prime is 428431955489. The next prime is 428431955509. The reversal of 428431955491 is 194559134824.

428431955491 = T₅₃₄₄₃₄ + T₅₃₄₄₃₅ + T₅₃₄₄₃₆.

It is a 11-Lehmer number, since φ(428431955491) divides (428431955491-1)¹¹.

It is a cyclic number.

It is not a de Polignac number, because 428431955491 - 2¹ = 428431955489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (428431955191) 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, 21240451 + ... + 21260611.

It is an arithmetic number, because the mean of its divisors is an integer number (14726324800).

Almost surely, 2^428431955491 is an apocalyptic number.

428431955491 is the 534436-th centered triangular number.

428431955491 is a deficient number, since it is larger than the sum of its proper divisors (42810438109).

428431955491 is a wasteful number, since it uses less digits than its factorization.

428431955491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20651.

The product of its digits is 6220800, while the sum is 55.

The spelling of 428431955491 in words is "four hundred twenty-eight billion, four hundred thirty-one million, nine hundred fifty-five thousand, four hundred ninety-one".