977321781 has 20 divisors (see below), whose sum is σ = 1460793312. Its totient is φ = 651171528.

The previous prime is 977321777. The next prime is 977321861. The reversal of 977321781 is 187123779.

It is not a de Polignac number, because 977321781 - 2² = 977321777 is a prime.

It is a super-2 number, since 2×977321781² = 1910315727234023922, which contains 22 as substring.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (977321771) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 257560 + ... + 261326.

Almost surely, 2^977321781 is an apocalyptic number.

It is an amenable number.

977321781 is a deficient number, since it is larger than the sum of its proper divisors (483471531).

977321781 is a wasteful number, since it uses less digits than its factorization.

977321781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6982 (or 6973 counting only the distinct ones).

The product of its digits is 148176, while the sum is 45.

The square root of 977321781 is about 31262.1461355423. The cubic root of 977321781 is about 992.3827180075.

The spelling of 977321781 in words is "nine hundred seventy-seven million, three hundred twenty-one thousand, seven hundred eighty-one".