972491778 has 16 divisors (see below), whose sum is σ = 2161092960. Its totient is φ = 324163908.

The previous prime is 972491777. The next prime is 972491789. The reversal of 972491778 is 877194279.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 18009107 = 972491778 / (9 + 7 + 2 + 4 + 9 + 1 + 7 + 7 + 8).

It is not an unprimeable number, because it can be changed into a prime (972491777) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9004500 + ... + 9004607.

It is an arithmetic number, because the mean of its divisors is an integer number (135068310).

Almost surely, 2^972491778 is an apocalyptic number.

972491778 is an abundant number, since it is smaller than the sum of its proper divisors (1188601182).

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

972491778 is a wasteful number, since it uses less digits than its factorization.

972491778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18009118 (or 18009112 counting only the distinct ones).

The product of its digits is 1778112, while the sum is 54.

The square root of 972491778 is about 31184.8004322619. The cubic root of 972491778 is about 990.7452056768.

The spelling of 972491778 in words is "nine hundred seventy-two million, four hundred ninety-one thousand, seven hundred seventy-eight".