394946976621 has 4 divisors (see below), whose sum is σ = 526595968832. Its totient is φ = 263297984412.

The previous prime is 394946976517. The next prime is 394946976679. The reversal of 394946976621 is 126679649493.

It is a happy number.

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.

It is not a de Polignac number, because 394946976621 - 2¹¹ = 394946974573 is a prime.

It is a super-2 number, since 2×394946976621² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394946976691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65824496101 + ... + 65824496106.

It is an arithmetic number, because the mean of its divisors is an integer number (131648992208).

Almost surely, 2^394946976621 is an apocalyptic number.

It is an amenable number.

394946976621 is a deficient number, since it is larger than the sum of its proper divisors (131648992211).

394946976621 is a wasteful number, since it uses less digits than its factorization.

394946976621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131648992210.

The product of its digits is 105815808, while the sum is 66.

The spelling of 394946976621 in words is "three hundred ninety-four billion, nine hundred forty-six million, nine hundred seventy-six thousand, six hundred twenty-one".