990645780 has 48 divisors (see below), whose sum is σ = 2808933120. Its totient is φ = 260827008.

The previous prime is 990645749. The next prime is 990645787. The reversal of 990645780 is 87546099.

It is a super-2 number, since 2×990645780² = 1962758122863616800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990645787) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99759 + ... + 109238.

It is an arithmetic number, because the mean of its divisors is an integer number (58519440).

Almost surely, 2^990645780 is an apocalyptic number.

It is an amenable number.

990645780 is an abundant number, since it is smaller than the sum of its proper divisors (1818287340).

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

990645780 is a wasteful number, since it uses less digits than its factorization.

990645780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209088 (or 209086 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 48.

The square root of 990645780 is about 31474.5258899955. The cubic root of 990645780 is about 996.8721534429.

The spelling of 990645780 in words is "nine hundred ninety million, six hundred forty-five thousand, seven hundred eighty".