661011456 has 176 divisors, whose sum is σ = 2051585280. Its totient is φ = 185303040.

The previous prime is 661011443. The next prime is 661011473. The reversal of 661011456 is 654110166.

It is a super-2 number, since 2×661011456² = 873872289926479872, which contains 22 as substring.

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, 1268476 + ... + 1268996.

Almost surely, 2^661011456 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661011456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1025792640).

661011456 is an abundant number, since it is smaller than the sum of its proper divisors (1390573824).

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

661011456 is a wasteful number, since it uses less digits than its factorization.

661011456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610 (or 592 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 661011456 is about 25710.1430567782. The cubic root of 661011456 is about 871.1033062685.

The spelling of 661011456 in words is "six hundred sixty-one million, eleven thousand, four hundred fifty-six".