90870461821 has 4 divisors (see below), whose sum is σ = 92410639200. Its totient is φ = 89330284444.

The previous prime is 90870461819. The next prime is 90870461849. The reversal of 90870461821 is 12816407809.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12816407809 = 59 ⋅217227251.

It is a cyclic number.

It is not a de Polignac number, because 90870461821 - 2¹ = 90870461819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90870461861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 770088601 + ... + 770088718.

It is an arithmetic number, because the mean of its divisors is an integer number (23102659800).

Almost surely, 2^90870461821 is an apocalyptic number.

It is an amenable number.

90870461821 is a deficient number, since it is larger than the sum of its proper divisors (1540177379).

90870461821 is a wasteful number, since it uses less digits than its factorization.

90870461821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1540177378.

The product of its (nonzero) digits is 193536, while the sum is 46.

The spelling of 90870461821 in words is "ninety billion, eight hundred seventy million, four hundred sixty-one thousand, eight hundred twenty-one".