921689040 has 80 divisors (see below), whose sum is σ = 2860674048. Its totient is φ = 245488128.

The previous prime is 921689003. The next prime is 921689057. The reversal of 921689040 is 40986129.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×921689040² = 1699021372912243200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 921689040.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 259114 + ... + 262646.

Almost surely, 2^921689040 is an apocalyptic number.

It is an amenable number.

921689040 is an abundant number, since it is smaller than the sum of its proper divisors (1938985008).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

921689040 is a wasteful number, since it uses less digits than its factorization.

921689040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4636 (or 4630 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 921689040 is about 30359.3320084616. The cubic root of 921689040 is about 973.1836585178.

The spelling of 921689040 in words is "nine hundred twenty-one million, six hundred eighty-nine thousand, forty".