1972721520 has 640 divisors, whose sum is σ = 8785152000. Its totient is φ = 394813440.

The previous prime is 1972721473. The next prime is 1972721551. The reversal of 1972721520 is 251272791.

1972721520 is a `hidden beast` number, since 1 + 97 + 27 + 21 + 520 = 666.

It is a super-2 number, since 2×1972721520² = 7783260390942220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4823076 + ... + 4823484.

It is an arithmetic number, because the mean of its divisors is an integer number (13726800).

Almost surely, 2^1972721520 is an apocalyptic number.

1972721520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1972721520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4392576000).

1972721520 is an abundant number, since it is smaller than the sum of its proper divisors (6812430480).

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

1972721520 is a wasteful number, since it uses less digits than its factorization.

1972721520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 466 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

The square root of 1972721520 is about 44415.3297860097. The cubic root of 1972721520 is about 1254.1666864800.

The spelling of 1972721520 in words is "one billion, nine hundred seventy-two million, seven hundred twenty-one thousand, five hundred twenty".