921678746 has 4 divisors (see below), whose sum is σ = 1382518122. Its totient is φ = 460839372.

The previous prime is 921678743. The next prime is 921678781. The reversal of 921678746 is 647876129.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 647876129 = 281 ⋅2305609.

It can be written as a sum of positive squares in only one way, i.e., 920212225 + 1466521 = 30335^2 + 1211^2 .

It is a junction number, because it is equal to n+sod(n) for n = 921678694 and 921678703.

It is not an unprimeable number, because it can be changed into a prime (921678743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 230419685 + ... + 230419688.

Almost surely, 2^921678746 is an apocalyptic number.

921678746 is a deficient number, since it is larger than the sum of its proper divisors (460839376).

921678746 is a wasteful number, since it uses less digits than its factorization.

921678746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460839375.

The product of its digits is 1016064, while the sum is 50.

The square root of 921678746 is about 30359.1624719787. The cubic root of 921678746 is about 973.1800354629.

The spelling of 921678746 in words is "nine hundred twenty-one million, six hundred seventy-eight thousand, seven hundred forty-six".