921690053 has 4 divisors (see below), whose sum is σ = 936799788. Its totient is φ = 906580320.

The previous prime is 921690031. The next prime is 921690061. The reversal of 921690053 is 350096129.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 350096129 = 4643 ⋅75403.

It can be written as a sum of positive squares in 2 ways, for example, as 138697729 + 782992324 = 11777^2 + 27982^2 .

It is a cyclic number.

It is not a de Polignac number, because 921690053 - 2²⁴ = 904912837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 921689995 and 921690022.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (921690013) 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, 7554776 + ... + 7554897.

It is an arithmetic number, because the mean of its divisors is an integer number (234199947).

Almost surely, 2^921690053 is an apocalyptic number.

It is an amenable number.

921690053 is a deficient number, since it is larger than the sum of its proper divisors (15109735).

921690053 is a wasteful number, since it uses less digits than its factorization.

921690053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15109734.

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 921690053 is about 30359.3486919598. The cubic root of 921690053 is about 973.1840150497.

The spelling of 921690053 in words is "nine hundred twenty-one million, six hundred ninety thousand, fifty-three".